Write on the six authentic collections of Hadith (Sihaus-Sittah).

The Sihah as-Sittah ("the six authentic collections") are the six books of Hadith that Sunni scholars regard as the most reliable records of the sayings, actions and approvals of Prophet Muhammad (S.A.W.). They were compiled in the third century of the Hijrah by scholars who applied rigorous rules of criticism to the chain of narrators (isnad) and the text (matn) of every report.

1. Sahih al-Bukhari - compiled by Imam Muhammad ibn Ismail al-Bukhari (d. 256 A.H.). It is ranked the most authentic book after the Qur'an. He selected roughly 7,000 traditions (with repetitions) from about 600,000, admitting only those meeting his strict conditions of continuous, trustworthy narration.
2. Sahih Muslim - compiled by Imam Muslim ibn al-Hajjaj al-Qushayri (d. 261 A.H.), a student of al-Bukhari. It is ranked second in authenticity and is praised for its excellent arrangement of traditions under single themes.
3. Sunan Abu Dawud - compiled by Imam Sulayman ibn al-Ash'ath as-Sijistani (d. 275 A.H.). It concentrates on Hadith dealing with legal rulings (ahkam) and jurisprudence.
4. Jami' at-Tirmidhi - compiled by Imam Muhammad ibn Isa at-Tirmidhi (d. 279 A.H.). Besides the traditions, he grades each as sound, good or weak and records the differing views of the jurists.
5. Sunan an-Nasa'i - compiled by Imam Ahmad ibn Shu'ayb an-Nasa'i (d. 303 A.H.). It is noted for its careful attention to defects in the chains of narration.
6. Sunan Ibn Majah - compiled by Imam Muhammad ibn Yazid ibn Majah (d. 273 A.H.). It contains some traditions not found in the others, though a number of them are of weaker grade.

Significance: These collections preserve the Sunnah in an organised and authenticated form, provide the second source of Islamic law after the Qur'an, guide Muslims in worship, morals and social dealings, and stand as a monument to the science of Hadith criticism developed by early Muslim scholars.