It is narrated from Sayyiduna Amr bin al-As (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) "taught him fifteen prostrations in the Qur'an, three of which are in the Mufassal surahs, and two prostrations are in Surah al-Hajj."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3727
Hadith Gradingمحدثین:حسن لغيره
Hadith Takhrij«حسن لغيره۔ من سند آخر اخرجه ابوداود 1401»