Muslims commemorate the fortieth day after the martyrdom of Imam Hussain (AS) and his companions, called Arbaeen, meaning the fortieth day in Arabic. They all gather around the city of Karbala and Imam Hussain’s (AS) shrine, mourning and lamenting the unfair and cruel war between his comrades and those of Yazid Ibn Muawiyah, which led into the death of those pure men and the bondage of their families. 

This commemoration happens every year around the city of Karbala. Muslims begin to walk to Karbala from other towns. They gather together in groups to pray, and especially to mourn the martyrdom of Imam Hussain (AS).
This walk is a hard one. It takes at least three days and lots of energy and time. So, why do Muslims take that? What is the philosophy behind it? 

To answer our questions, first, let’s have a review of the history behind this walk and then move to the other aspects of this commemoration. 

1. What is the Arbaeen Walk?

The history of Arbaeen walk goes back to the first visitors of Imam Hussain (AS) after his death. On the day of Arbaeen, forty days after the tragic martyrdom of Imam Hussain (AS), Imam’s (AS) son, sister and the remaining members of his family and that of the other martyrs came back to Karbala to lament the death of their dear ones besides their graves.  

Their next visitor was Jabir Ibn Abdullah Ansari on the year 61 AH. Visiting Imam Hussain’s (AS) shrine was a tradition in Shiite culture until a short period after Morteza Anasari’s became the religious reference (Marja’) of Shiite Muslims. It was then lessened for some years and then revived. Some other religious references (Marja’) kept this tradition alive among their followers, until the government of Saddam Hussain, which banned all religious Shiite traditions to be performed publically [1]. 

The tradition was revived after the fall of Saddam, and it is still to be continued. 

2. Why on Foot?

Visiting the holy shrines and going on pilgrimages on foot is not something new or belonging to our age. It’s got a long history, and Adam did the first pilgrimage on his visit to Mecca [2]. It isn’t a tradition just among Muslims either. It is performed in other faiths and religions, too. For instance, Caesar made a vow to his God to go on a pilgrimage to the Dome of Rocks if he won the battle against the Empire of Persepolis (Iran). He performed his vow after his victory [3].

Pilgrimages are highly admired, and their act is seen as a way of getting closer to Allah by Imam Sadiq (AS). Visiting the holy shrines of the twelve Imams (AS) is even more praised, especially the sacred shrine of Imam Hussain (AS). Of course, it’s not these shrines themselves that are of value and importance, but the people who have been buried there. Thus, when one makes a pilgrimage toward these shrines, he/she finds the chance to think more about these great personalities who won Allah’s satisfaction and praise and were Muslims in the real sense of the word. So, in every step that a pilgrimage takes toward Imams' (AS) shrines, especially that of Imam Hussain (AS), he/she is getting closer to a source of spiritual blessing, bringing him/her thousands of virtues and wiping away thousands of vices from his/her mind and soul.

3. What is the Philosophy behind the Arbaeen Walk?

The Arbaeen pilgrimage is not merely a long walk. Instead, it is a kind of movement in which despite being in publics, pilgrims have their own private relationship with Allah and Imam Hussain (AS), which finds a new form of divine immaterial dependence and conformance. Thinking about the goals and the history behind the martyrdom of Imam Hussain (AS), the injustice and cruelty imposed on his family and the devotions of his faithful followers brings about many personal and social growth and improvements. 

Meeting other Muslims, exchanging ideas, and making friendships with Muslims of the other countries is another social outcome of this pilgrimage. One finds out that they are not alone in their faith, and have friends all over the world. They may have differences, but they have one thing in common: Belief in Imam Hussain (AS) and his right cause. 

The last and the most crucial point to mention this great gathering is it's a kind of preparation for the grand reappearance of Imam Mahdi (AS), the awaited savior among Muslims. The Arbaeen pilgrimage is to make the minds and souls ready for this great event. It is said that when Imam Mahdi (AS) reappears, he introduces himself as the son of Hussain (AS) [6], whose fame has reached many people through the Arbaeen Pilgrimage; one of the most significant religious gathering around the world, with the estimated number of 40,000,000 people participating in it, whose news is broadcasted all over the world [5].  

References

1. "The background of Arba'een rally/The importance of Najaf-Karbala rally from the scholar's viewpoint." Fars News. Archived from the original on 16 November 2015. Retrieved 4 October 2015.
2. Hor Ameli, Muhammad Bin Hussain Vasayel-o-Shia, Vol 11, p 132
3. Sobhani, Jafar The Light of Eternity p. 696
4. Kamel-o-Ziyarat: Pp 183, 184 and 185
5. Philipson, Alice (19 January 2015). "The ten largest gatherings in human history." The Telegraph. Archived from the original on 6 October 2015. Retrieved 3 October 2015. 
6. Khademi Shirazi, Mohammad Yad’e Mahdi P16, P132

1.  Planting Trees

Each fruit of the tree you have planted will be appreciated by a reward from Allah. 
Kanz al-Amaal, vol.12, p.341.

2.  Learning during Youth

What is learned during youth, like an engraving on a stone, will never be forgotten. 
Bihar al-Anwar, vol. 1, p. 222.

3. Mothers

Heaven lies beneath the feet of mothers. 

Mizan al-Hikmah, hadith no. 22691.

4. Respecting The Elderly

Respecting a Muslim elderly is like showing respect to Allah.
Usul al-Kafi, vol.2, p.165.

5. The Sources of  Mercy

The elderly are the sources of mercy and divine blessing.
Nahj al-fasaha, p.222.

6. The Most Generous according to Prophet Muhammad (PBUH&HP)

The most generous among you is the one who spreads what he has learned among people.
Mizan al-Hikmah, hadith no. 13825.

7. The Faithful  

The faithful are tied in kindness and affection together like members of a body, one’s pain and hardship affect the others. 
Bihar al-Anwar, vol.58, p.150

8.  Marriage 

The one who gets married has completed half of his/her religion. 

Kanz al-Amaal, hadith no.44403.

9. The Mission of Prophet Muhammad (PBUH&HP)

Indeed, I have been sent to revive the virtues and good morals.
Bihar al-Anwar, vol.16, p.286.

10.  Playing during Childhood

Playfulness during childhood will elevate one in wisdom in his/her adulthood.
Nahj al-Fasaha, p.564, Hadith no. 1940.

11.  The Closest Ones

The kindest, most amiable, generous, patient, and just among you is the closest to me in manner.   
Usul al-Kafi, vol.2, p.240-241.

12. Treating Children 

Be childlike with children.                                                                                                                                                                                                                                

Man la Yahduruhu al-faqih, vol.3, p.483.

13.  Keep Your Promises to Children 

Love children and be kind to them and keep your promises to them since they only know you as their providers.
Usul al-Kafi, vol.6, p.49.

14. The One Who Wins Allah's Praise  

Allah’s love and praise be upon the one who helps his/her children by doing good to them, caring for, and educating them. 
Mustadrak al-Wasaiil, vol.15, p.169.

15. Greeting Children, Prophet Muhammad (PBUH&HP)'s Tradition

There are five activities that I won’t leave off till I’m alive so that they would become part of my tradition. [One of them] is greeting children.
Makarem al-Akhlaq, vol.1, p.251.  

16. Fathers   

Being like your father is one of the best blessings of Allah to you.
Bihar al-Anwar, vol.71, p.84.

17. Looking Kindly at Your Parents   

The kind look of a child to his/her parents is as praying in Allah’s regard. 
Tuhaf al-Uqul, p.46.

18. Treating Your Family 

The best among you is the one who treats his family best, and I am better than all of you for my family.
Nahj-al fesaha, p.472, Hadith no. 1520.

19. The Desired Family    

Whenever Allah desires the best for a family, He raises their awareness about the religion. The younger ones respect the elders, they observe moderation in their expenses, and they would know about their faults to make them right. 
Nahj-al Fasaha, p.181, Hadith no. 147

20. Delighting Your Parents  

Whoever delights his/her parents, has delighted Allah and the one who displeases them has displeased Allah.
Ali ibn Abd-al-Malik al-Hindi, Kanz al-Ummal, vol.16, p.470.

21.  Imam Ali (AS)

Whomever I am his/her leader (Mawla), then Ali is his/her leader (Mawla). 

Musnad Ahmad ibn Hanbal, vol.4, p.370. 

22. Women's Status in Allah's Regard

Women are held dearer in Allah’s regard than men, and Allah will highly reward any man who brings joy to his Mahram women.  
Usul al-Kafi, vol.6, p.7.

23. Martyrdom of Imam Hussain (AS)

Martyrdom of Imam Hussain (AS) has ignited the hearts of believers with a pain that will never be subsided.
Jami al-Ahadith al-Shia, vol 12., p.556.

24. A Good Friend 

When Allah wants to pour His blessings upon you, He endows you with a Good Friend. 
Nahj al-Fasaha, p.776. 

25. Allah's Favorite    

When Allah chooses to favor someone, He makes him the source of satisfying other people's needs. 

26. Lady Fatimah (AS)  

Fatima is of my flesh, who is the light of my eyes and the warmth of my heart.
al-Shaykh al-Saduq, Al-Amali, p.486.

27. Humanity    

Loving Humanity is second only to having faith in Allah as one of the best deeds in Islam. 
Nahj al-Fasaha, p.74,  Hadith no. 387.

28.  An Act of Charity

If a Muslim plants a tree or any plant and a human, bird, or any other animals use it, Allah counts it as an act of charity.” 
Mustadrak al-Wasaiil, vol.13, p.460.

29. Lying      

Lying would negatively influence your livelihood.
Nahj al-Fasaha, p.373, Hadith no. 1087.

30. The Most Honest, Steadfast and Kindest   

On the Day of Judgment, those who were most honest in their words, steadfast in their promises and kindest in their manners, will be the closest ones to me.
Al-Shaykh al-Tusi, Al-Amali, p.229.

31. The Lawful (Halal) Earning

Praying has seventy parts, the most important and biggest of which is lawful (Halal) earning. 
Mustadrak al-Wasaiil, vol.13, p.12.

32. Performing Prayers

The most praised deeds in Allah’s regard is performing prayers (Salat) on their due time.
Kanz al-Amal, vol. 7, Hadith 18897.

33. A Desired Companion

The most desired companion is like a perfumer; his/her perfume would reach you, even if he/she didn't give you anything.

Kanz al-Amal, vol.9, Hadith 24676.

34. Eating Less  

Eating less results in a healthier body and a more tender heart while overeating makes one sick and hard-hearted. 
Mizan al-Hikmah, Hadith 579.

35. "I Love You"  

The words of “I love you,” said by a man to his wife, will forever be engraved upon the woman’s heart. 
Wassail al-Shia, vol. 14, p.10.

36.  Causing Harm   

Causing harm to yourself and others is forbidden in Islam.
Usul al-Kafi, vol.5, p.292.

37. Security and Health 

There are two blessings to which no one gives thanks: security and health. 
Khisal, p.34. 

38. The Most Grateful Person    

The most grateful person is the one who thanks people most.

Nahj al-Fasaha, Hadith no. 312.  

39. Saving someone's Reputation   

Whoever saves a believer’s reputation will surely be rewarded by heaven. 
Al-Shaykh al-Saduq, Thawab al-a'mal wa 'iqab al-Amal, p.145.

40. Ignorance and Wisdom  

No lack is more irritating than ignorance, and no wealth is more advantageous than wisdom.  
Ususl al-Kafi, vol.1, p.25-26, Hadith 25