Every day we meet several people at work, in the shops, at the university, in the neighborhood, or at parties and gatherings with whom we communicate and interact. Talking, telling jokes, shaking hands, touching or kissing usually happen in these interactions; but, is a Muslim allowed to do all these with whoever he/she wants? Or is he/she permitted to be exposed to such acts?  These and many similar questions are answered in Islam.

To clarify and form the relations among people, Islam has presented the concept of Maharim and the two categories “Mahram” and “non-Mahram” which sometimes serve as conditions, requirements, or the basis of several Islamic laws. Regarding the Islamic rules on marriage, these categories define who a person can and cannot marry. Likewise, when dealing with the Islamic dress code, i.e., explaining whom one must cover specific parts of a body in front of, the concept of Maharim is required.

Who is Mahram?

One’s Mahram is anyone whom it is permanently forbidden to marry because of blood ties, marriage ties or breastfeeding. However, a woman does not need to cover her hair and put on Hijab when she is in their presence.  A woman's male Mahrams fall into three categories plus her spouse [1]. Mahrams for a man are derived similarly. The Maharim for both, extracted from the verses of the Holy Quran (4:22-23) and (24:31), are listed below [1], and all other people and relatives are considered as non-Maharams.

Categories of Maharim

Permanent or blood Mahrams, with whom one is Mahram through blood ties:
parents, grandparents, and further ancestors;
siblings;
children, grandchildren, and further descendants;
siblings of parents, grandparents, and further ancestors (cousins and their children are not Mahram);
children and further descendants of siblings;
In-law Mahrams, with whom one becomes Mahram through marriage ties:
father-in-law, mother-in-law;
son-in-law, daughter-in-law;
stepfather (mother's husband) if their marriage is consummated, stepmother (father's wife) even if their marriage is not consummated;
stepson (husband's son) even if their marriage is not consummated, stepdaughter (wife's daughter) if their marriage is consummated[i];
Rada or "milk-suckling Mahrams," with whom one becomes Mahram because of being breastfed by her. When a woman breastfeeds an infant that is not her child for a certain amount of time under certain conditions, she becomes the child's rada mother and everything concerning blood Mahrams apply here, such as rada father/mother, rada sister/brother, rada aunt/uncle and so on. In English, these can be referred to as milk-brother, milk-mother, etc. [ii].

Maharim and Marriage

It is forbidden (Haram) to marry Mahrams, but one can marry non-Mahrams who have reached puberty. As explained above, Married couples are Mahram to each other. But unlike other Mahrams, the limitations and rulings on looking and touching do not apply to them; i.e., married couples are the only ones allowed to touch and look at the whole body of one another; even the private parts. 

Maharim and Social Interactions

Regarding social interactions, there are some rules according to the concept of Maharim:

Women and men are both required to keep their gazes downcast and should not stare at the other person when facing non-Mahrams or talk to them. Even Mahrams are not allowed to see certain parts of the body of each other (this will be discussed more under a separate topic “the Islamic rules on looking“);
When talking to non-Mahrams, the tone of voice should be serious, and the dialogues should be direct and as much as necessary. One should also avoid telling jokes and laughing loudly [iii];
Any physical contact (i.e., shaking hands, hugging touching) with non-Mahrams is forbidden (haram), except for curing patients. In this case, if a doctor of the same gender as the patient exists and can cure, then it is forbidden to refer to a non-Mahram doctor.
When being sole in a closed room (where no one else can enter, i.e., locked place), it is forbidden for a non-Mahram man to remain alone in the company of a non-Mahram woman. The Prophet of Islam (PBUH&HP) said: “No man is alone with a woman except that Satan is the third one present ” [2];
It is required (Wajib) to cover specific parts of a body in the presence of a non-Mahram according to the Islamic dress code. For men, this includes from navel to knee. For women, the clothing should cover their hair and body, but covering the face and the hands, from the wrist to the fingers, is not mandated [3].

Notes:
[i] sister-in-law and brother-in-law are not Mahram.

[ii] Refer to your source of emulation (Marja’ Taqlid) for more details and the rulings.

[iii] See the article on modesty.

References: 

1. Mahram and non Mahram
2. S. H. al-Amili, “Wasail al-Shia”, vol. 20, p. 131.
3. A. Aroussi Howayzi, “Tafsir Noor al-Thaqalayn”, vol. 3/589, T. 105.

1. Speak at the Right Time

Don’t speak when it’s not a good time to talk. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no. 10274. 

2. A Day of Celebration

Any day on which you don’t commit sins or disobey Allah is a day of celebration (Eid). 

Nahj al-Balagha, Wisdom no.428. 

3. The Effect of Nature 

Looking at nature brings happiness.

Nahj al-Balagha, Wisdom no.400. 

4. Two Valuable Blessings in Imam Ali (AS)'s Words 

There are two things whose worth you will find out only after losing them; youth and health.

Ghurar al-Hikam wa Durar al-Kalim, vol. 1, p.449.

5. Difference with Children 

Do not impose your own traditions on your children, since they are living in a different era than yours. 

Ibn abi al-Hadid, Interpretation of Nahj al-Balagha, vol.20, p.286. 

6. Who to Consult and Who not to Consult

Consult with your wise enemy, but avoid your ignorant friend’s advice. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.2471.

7. The Best Candidates to Consult

The wise, knowledgeable, experienced, and prudent ones are the best to consult with. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.4990.

8. When to Consult 

Consult before making decisions and think before taking action.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.5754.

9. Be Patient with Your Job's Difficulties 

If you don’t endure the difficulties of working, you are made to bear the misfortunes of poverty.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.8987.

 10. Be Kind

Be kind to the less privileged ones than you, so that your superiors be kind to you. 

Muhammadi Reyshahri, Mizan al-Hikmah, Hadith no. 6960. 

11. Respect Your Father and Teacher

Rise in respect to your father and your teacher, even if you possess a high status. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.2341.

12. The Foundation of the World according to Imam Ali (AS)

The world is founded on justice. 

Muhammadi Reyshahri, Mizan al-Hikmah, Hadith no. 11955. 

13. Observe Justice 

The fairest among you is the one who observes justice between people while in power.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.3242.

14. Treat others as you expect to be treated

The fairest manner is to treat people the way you expect them to treat you. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.3170.

15. Quality is more important than Quantity for Imam Ali (AS)

Don’t worry about how fast you do a job; instead, observe the best quality in whatever you do. 

Ibn abi al-Hadid, Interpretation of Nahj al-Balagha, vol.20, p.267. 

16. The Worst Homeland

The worst homeland is the one that doesn’t keep its citizens safe. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.5712.

17. How to Start a Deed

You need to have enough knowledge of a deed before doing it. 

Nahj al-Bakagha, p.171.  

18. Do Every Deed on its Own Time 

Do every day’s work on that specific day, since each task is due to its special day. 

Nahj al-Balagha, letter no.53.  

19. Keep Your Promises

The ones who don’t keep their promise do not believe in Allah. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.9577.

20. Don't Break Your Promise to Children 

It’s beneath you to make a promise to your child and not keep it. 

Al-Shaykh al-Saduq, Al-Amali, p.342. 

21. Be Childlike 

If you have a child, be childlike with him/her. 

Usul al-Kafi, vol.6, p.50. 

22. Yesterday, Tomorrow, Today 

Yesterday is gone, tomorrow is yet to come, while today is a precious chance for you to make the most of it.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.9840.

23. An Unplanted Land

The heart of the teenage is like an unplanted land that is ready to receive any seed planted in it. 

Nahj al-Balagha, letter no. 31. 

24. Read Books

The greatest peace is obtained by reading books. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.8126.

25. Scholars' Heaven 

Find the scholars’ heaven within the pages of the books. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.991.

26. The Perfection of Religion

The perfection of religion is in seeking knowledge and making use of it. 

Usul al-Kafi, vol.1, p.30.

27. What is Said not Who Said it 

Pay attention to what is said, not who is saying it. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.5048.

28. Think instead of Talking

Try to ponder and understand instead of quoting. 

Muhammadi Reyshahri, Mizan al-Hikmah, Hadith no. 3355.

29. Help Others

You will be helped, the same way as you help others. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.7209.

30. The Faithful as Defined by Imam Ali (AS)

The faithful who help the destitute in the hardships and misfortunes of their lives are loved most by Allah.

Tuhaf al-Uqul, p.376.

31. Peace is Better Than War

I found peace, so far as it won’t degrade Islam, more beneficial than war. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.10138.

32. You Make a Mistake, too!

Don’t be happy about the mistakes of others, since you are not perfect either. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.10294.

33. Respect to be Respected 

Talk respectfully to people to hear respectful responses. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.2568.

34. The Power of Optimism 

Optimism reduces despair and keeps you away from committing sins. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.4823.

 35. Do not Measure Truth Based on People 

What is right is not distinguished by the people; You should first know what is right to find the ones following it.

al-Fattal al-Neyshaburi, Rawḍat al-wāʿiẓīn wa baṣīrat al-muttaʿiẓīn, p.31.

36. Be at Peace

Whoever avoids holding grudges, his/her heart and mind will remain at peace. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.8548.

37. Be Thankful and Patient 

Be thankful to Allah on your days of comfort and happiness, and be patient on the days of difficulty and hardship.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.7148.

38. The Precious Blessing of Health 

Health is more precious than any other of Allah’s blessings. 

Ghurar al-Hikam wa Durar al-Kalim, p.483.

39. Women in Islam

Women are Allah’s trusts upon you, do not hurt them, and do not put pressure on them.

Mustadrak al-Wasail, vol.2, p.551.

40. Make the most of Your Happy Moments 

Enjoy your moments of happiness with all your heart to help you at the time of sadness. 

Ibn abi al-Hadid, Interpretation of Nahj al-Balagha, vol.20, p.286.