Dr. Susmit Kumar
The Sharia is Islamic law, which is based mainly on the hadith, or sayings of Muhammad. For the first few decades, hadith were circulated by the companions of Muhammad. Later, people began fabricating them to suit their own purposes.
An effort was started to collect hadith and eliminate dubious ones using certain verification processes in the 7th century. Sunni Muslims consider there to be six major collections. Out of these six, the Sahih (The Verified) of al-Bukhari is considered most reliable.
Al-Bukhari was born in Bukhara, present day Uzbekistan, in year 194 of the Hejira (A.D. 816) and died in year 248 of the Hejira (A.D. 870). An eminent scholar, he traveled throughout the Islamic world to Syria, Iraq, Egypt, and the Hijaz, a region west of Saudi Arabia having Mecca and Medina. He was able to interview 1,080 persons and to collect 600,000 hadith.  Out of some 200,000, not counting additional thousands that he rejected without examination, he selected only 7,300 as authentic. His works consist of 97 books divided by subject of interest into 3,450 chapters. Even so, Muslims kept many of the rejected hadith in circulation. They eventually boiled down to 2,762 in all.
Muhammad continued most pre-Islamic Arabian traditions. Shahrastani (d. 1153), a 12th century historian, in his Al Milal wal-Nihal documents interesting traditions with respect to monotheism, resurrection, and certain specific rituals of pre-Islamic Arabia that were identical to those of the Islamic period. The customs of proclaiming divorce thrice to end a marriage, of washing after sexual intercourse, of ghusl (washing the cadaver before burial), and of the general cleaning of the body were all practiced in pre-Islamic Arabia.
Muhammad also perpetuated the old legal system—“an eye for an eye.” Because there was no police or prison system, the only punishment given to a criminal was equivalent to the crime he committed. Nevertheless, Muhammad did foster the individualism that was beginning to appear in Arabia; thus, the Quran decrees that a murdered man’s relatives can punish only his murderer, not just any member of his tribe, as in the old system.
1 Mernissi, Fatima, The Veil and the Male Elite, Perseus Books, Cambridge, Massachusetts, 1991, p. 44.
2 Gibb, H.A.R., Muhammadenism, Oxford University Press, London, 1949-1950, p. 79, referenced in Vaziri, Mostafa, op. cit., p. 50.
3 Shahrastani, Muhammad b. Abdulkarim b. Ahmed, Al Milal wal-Nihal, Vol II, 2nd ed., Offset Co., Tehran, 1979, p. 373-416, referenced in Vaziri, Mostafa, op. cit., p. 14-15.
4 Watt, Montgomery W., Muhammad at Medina, Oxford, 1956, p. 268, referenced in Armstrong, Karen, op. cit., p. 230.