Allah Almighty says: "Or has he not been informed of what is in the scriptures of Musa (peace be upon him), and of Ibrahim (peace be upon him), who fulfilled (his covenant)?" [Surah al-Najm: 36-37]
Imam al-Shafi'i (may Allah have mercy on him) said: "The recitation of the Book of Ibrahim (peace be upon him) is not known." And he mentioned the Zabur of Dawud (peace be upon him) and said: "And indeed it (the Qur'an) is in the scriptures of the former peoples." [Surah al-Shu'ara: 196]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجزية / Q18649
Sayyiduna Wathilah bin al-Asqa' (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him): "The scriptures of Ibrahim were revealed on the 1st of Ramadan, the Torah was revealed on the 6th of Ramadan, the Injil was revealed on the 13th of Ramadan, the Zabur was revealed on the 18th of Ramadan, and the Qur'an was revealed on the 24th of Ramadan."
(b) Al-Hasan al-Basri (may Allah have mercy on him) says: Allah Almighty revealed 104 books from the heavens.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجزية / 18649