The Quran is the final book of Allah and the main source of guidance for Muslims. It was revealed in the Arabic language to Prophet Muhammad (PBUH) over a period of approximately 23 years. Its revelation began in the month of Ramadan, when the angel Jibreel (AS) brought the first verses in the Cave of Hira. These first verses belong to Surah Al-Alaq. Jibreel (AS) continued to bring the revelation to the Prophet (PBUH) until the Quran was complete.
The Quran contains 114 chapters, called Surahs, and it is also divided into 30 equal parts, known as Juz or Para. The first Surah is Al-Fatiha, and it is recited in every rakat of Salah. The last Surah is An-Nas. The longest Surah is Al-Baqarah, which also contains the famous verse Ayat al-Kursi. The shortest Surah is Al-Kawthar, which has only three short verses. Surah Ya-Sin is known as the Heart of the Quran. Every Surah begins with Bismillah except Surah At-Tawbah.
Alongside the Quran, the teachings of the Prophet (PBUH) guide Muslims in daily life. The word Hadith refers to the sayings, actions, and silent approvals of the Prophet (PBUH), which were narrated by his companions. The word Sunnah means the way and practice of the Prophet (PBUH), which Muslims follow as an example. Hadith and Sunnah explain the meaning of the Quran and show how to apply it in practice.
After the time of the Prophet (PBUH), scholars worked carefully to collect and verify the Hadith. Among the Sunni scholars, the most authentic collection after the Quran is Sahih al-Bukhari, compiled by Imam Bukhari. Sahih Muslim was compiled by Imam Muslim ibn al-Hajjaj. These two books, along with four others, form the six main Hadith books known as the Sihah Sittah. The scholars examined the chain of narrators of each Hadith to make sure that it was reliable.
Many companions narrated Hadith, but the companion who narrated the largest number was Hazrat Abu Hurairah (RA). His memory and his constant company with the Prophet (PBUH) helped preserve thousands of narrations for the Muslim community.