Once Imam Sajjad (AS), the fourth Shiite Imam, heard a beggar asking people for charity on the 9th day of Dhu al-Hajjah, the day of Arafah. Imam Sajjad (AS) was surprised and said: 

Shame on you! Are you asking somebody for help other than Allah on this holy day? While on this day, even the fetus in the uterus hopes that Allah might grant them a happy future in the world (1)

As Imam Sajjad (AS) said, the day of Arafah is the day of Allah’s great mercy toward humanity. There are two important occasions in the Islamic calendar that are considered as the most important ones: the day of Arafah and the night of Qadr.

The Arafat plain

On the second day of their pilgrimage, hajj pilgrims must stay in the Arafat plain from noon until sunset, praying and seeking forgiveness from Allah Almighty and thanking Him for the opportunity to perform Hajj. This is known as “Wuquf in Arafat”. The Arafat plain is a special place near Mecca, and it is said that no one has ever sinned in this plain. 

There is also a mountain named Arafah in this plain, also known as “Jabal ar-Rahmah” which means “the mountain of Mercy”. About this mountain, Imam Baqir (AS) said:

Anyone who stays on this mountain, Allah will grant them their wishes. For the good people, Allah will grant all their wishes whether they are about this world or the Hereafter but for the bad people, only their worldly wishes will be granted (2)

Prophet Muhammad (PBUH & HP) stood on this mountain in his last days and bid farewell to his followers. 

Praying in this day

The most important practice for all the pilgrims in Mecca and those who couldn’t make it there is praying. 

Ibrahim ibn Hashim, one of the Shiite scholars, once saw Abdullah ibn Jundab, one of the pupils of Imam Kazim (AS), in the Arafat plain. He said, “I saw no one like him in the plain; his hands were up in prayer all the time, shedding tears that dropped onto the earth. When people left, I told him ‘I didn’t see no one praying like you in this plain’. Abdullah ibn Jundab replied ‘I swear to Allah that I prayed only for my brothers (other Shiites) because Imam Kazim (AS) told me that anyone who prays on this day for their brothers will be called from the heavens, and Allah has given them thousand more things than what they wished for their brothers’”. (3)

Imam Ali (AS) said:

It is not obligatory for the people to gather in the Arafah Day, except if they are in Mecca, but it’s no problem if people gather in the other cities and call upon Allah together. (4)

Sudair as-Sirafy, one of the pupils of Imam Sadiq (AS), asked him about fasting in the Arafah day. Imam Sadiq (AS) said “My father wouldn’t fast on this day [and I won’t neither]”. Sudair asked: “why don’t you?” Imam Sadiq (AS) said:

The Day of Arafah is a day of supplicant and prayer. Therefore, I worry that fasting would make me weak and I couldn’t pray enough, so I don’t want to fast on this day. (5)

There are some famous prayers narrated from the Shiite Imams that should be recited on this day. Imam Hussain (AS), before he moved to Karbala, stayed in the Arafat Plain and prayed humbly with his hands raised, asking Allah for forgiveness and mercy. This beautiful prayer is full of teachings about Allah and its recitation is highly recommended. Shias mostly go to holy places like mosques and shrines and recite this prayer together. 

Imam Sajjad (AS) also has a prayer exclusively for this day, which is written in the book “Sahifah as-Sajjadiah”. 

Other recommended practices

Other than praying, there are some rituals mentioned in the hadiths that one can do on this day:
•    Those who can’t make it to Mecca can visit the shrine of Imam Hussain (AS) in Karbala. In this regard Imam Sadiq (AS) said,

Anyone who makes pilgrimage to Karbala and washes their body in the Forat (a famous river there), and then goes to the shrine of Imam Hussain (AS), for every step they take, Allah considers it like a pilgrimage of Hajj”. (6)

•    Giving charity to the needy ones
•    Performing ghusl (a ritual bath) 
•    Fasting. Imam Ridha (AS) said,

Fasting on the day of Arafah is equal to fasting for a year. (7)

However, as Imam Sadiq (AS) mentioned, if fasting weakens you and hinders your prayer, it’s better not to fast. 

Resources 

1.   Man la Yahduruhu al-Faqih, Sheikh Saduq, vol.2, pg.211
2.   Vasa’il ash-Shia, Sheikh Hurr al-Ameli, vol.13, pg.546
3.  Vasa’il ash-Shia, Sheikh Hurr al-Ameli, vol.13, pg.544
4.   Vasa’il ash-Shia, Sheikh Hurr al-Ameli, vol.13, pg.561
5.   I’lal ash-Shara’I, Sheikh Saduq, vol.2, pg.386
6.   Al-Kafi, Sheikh Koleini, vol.4, pg.580
7.   Al-Istibsar, Sheikh Toosi, vol.2, pg.133
    

One of the main differences between Islamic and non-Islamic lifestyle is manifested in the eating habits. Not eating pork and not drinking wine are two of these practices which are indeed evident in the life of a Muslim.  This article will briefly analyze some of the reasons why Muslims do not consume pork.  

However, it is important to keep in mind that the central philosophy behind all religious rules including Islamic rules and regulations is only known by the All-Wise and All-Knowing God who is the Creator of the whole universe and all the creatures.

Religious Reasons:

Pork is forbidden in different Divine religions. For instance, the Bible says about pork: "And the swine ...  he is unclean to you. Of the flesh shall ye not eat, and their carcass shall ye not touch; they are unclean to you." (Leviticus, 11:7-8). The same command is repeated in Deuteronomy, 14:8.

Christians often depict Satan in religious anecdotes in the form of a pig. The Gospel of Barnabas mentions that Pig is Satan personified and that the pig’s body has the spirit of Satan. The present Bible among the Christians (Matthew 8-32 Marks 5-13, Luke 8: 28-39) describes how Jesus thrust the soul of Satan inside the herd of swine and sent them towards the river [1].

In Islam, there are two primary sources for understanding the orders of Allah: the Quran and the Sunnah [2].  Both the Holy Quran and Sunnah have equal status as far as the obligatory orders (wajibat) are concerned. If one wajib is mentioned in Sunnah only, it has the same weight as one said in the holy Quran only [3] and vice versa.  Both sources mention that eating pork is forbidden.

Allah has announced that eating pork is forbidden in several verses of the Holy Quran:

“You are prohibited carrion, blood, the flesh of swine …” (5:3).

The unclean nature of swine flesh is stated in the following verse:

“Say, ‘I do not find in what has been revealed to me that anyone be forbidden to eat anything except carrion or spilled blood, or the flesh of swine —for that is indeed unclean— or an impiety offered to other than Allah.’ …” (6:145)

The same concept is declared in the verses (2:173) and (16:115).

Imam Reza (AS) mentions regarding the prohibition of pork, “The Almighty Allah has prohibited (made Haram) Pork because it is a horrible and dreadful animal that Allah has created for men to derive lessons from. People should also refrain from sensuality and shameless deeds that cause such a terrible appearance. And that they fear from being transformed into pigs by Almighty Allah. (In the description of past nations it is mentioned that people who committed sexual promiscuity are changed into pigs in the Intermediate world (Barzakh) [i], and they shall be raised as pigs in the Judgment Day (Qiyamat)).

Also, pigs were allowed to exist so that they are a reminder of the metamorphosis (Maskh) [ii] of previous nations into pigs. The second reason for prohibiting pork is that the staple diet of pigs consists of extremely impure (Najis) and filthy things, and its blood contains innumerable harmful germs.” [4]

Imam Sadiq (AS) said,“The Almighty Allah metamorphosed many nations into animals. Among them are pigs, monkeys, and bears, etc. After this these animals were prohibited from being eaten so that people derive lessons from them and do not consider the sin minor.”[5]

Pork is very harmful to the body but we mention below only some of its harmful effects.

Scientific Reasons:

The present-day science of parasitology has proven some serious diseases in human beings caused by the bacteria and germs found in pork.  Pork is the main carrier of many germs and parasites such as Faciolopsis buski, Paragonimus, Clonorchis sinesis, Erysipelothrix rhusiophathiae [6]. Moreover, Dr. Joseph Mercola has cited the following diseases caused by pork: Porcine Reproductive and Respiratory Syndrome (PRRS), the Nipah Virus, Porcine Endogenous Retrovirus (PERV) and Menangle Virus [7].

On the whole, the pig is the cause of many serious and fatal diseases, among them, dysentery, trichinosis, tapeworm, roundworm, hookworm, jaundice, pneumonia, suffocation, intestinal obstruction, acute pancreatitis, enlargement of liver, diarrhea, emaciation, stone formation in liver, cancer, anemia, high fever, hindrance of growth development in children, typhoid, lameness, heart trouble, abortion, sterility, and sudden death [8].

It is important to note that despite hard efforts in medical science, many of the pig parasites cannot be eliminated by antibiotics, drugs or vaccines.

Some people assert that by present day means it is possible to eliminate all these parasites and make pork devoid of them, but even upon the supposition that use of sanitary equipment or cooking of meat at high temperatures eliminates all the parasites, nevertheless the harms associated with pork cannot be denied for according to the incontrovertible law, the meat of every animal bears the traits of that animal and, by means of the glands and the hormones secreted by them, influences the conduct of those who consume it.

Thus, consuming pork may transfer the attributes of sexual depravity and indifference towards the affairs of the womenfolk of the family - the most blatant traits of the male members of this species - into the person who consumes it.  And perhaps, one of the reasons for the excessive sexual profligacy dominant in the West could be consumption of the meat of this sordid animal [9].

So since the scope of science and the knowledge of human beings are limited, there might be other harms still undiscovered. However, even if human beings find some way of eliminating all the physical and spiritual harms of something, it does not mean that the forbidden (Haram) law of God becomes permissible (Halal). As mentioned at the beginning of the article, we must submit to the will of God as the Creator of the whole world and the Only One who truly knows about what is good and bad for the creatures and why.

Notes:

[i] The stage between this world and the hereafter

[ii] In Arabic, Maskh means for something to change form to an uglier one. In the Quran and Islamic tradition, this term refers to a specific divine punishment which was sent upon the wrongdoers and wrongdoing nations in the past (of course not all wrongdoers, but those who committed certain wrong acts) which can be called metamorphosis. For more information, please refer to http://www.islamquest.net/en/archive/question/fa614

References:

1. eating in Islam
2. Sunnah means the sayings, actions and silent approval of the Holy Prophet and the Holy Imams (PBUT).
3. islamic laws
4. Uyun al-Akhbar ar-Riďa & Wasa’il al-Shia, ch.1 
5. food in Islam
6. eating pork in Islam
7. all about pork meat