Sahih Muslim
The Book of Faith (Kitab Al-Iman)
Book Number: 001 / Hadith Number: 391
Abu Huraira reported: The Messenger of Allah (may peace be upon him) said: There was for every apostle a prayer with which he prayed for his Ummah and it was granted to him; but I wish, if Allah so wills, to defer my prayer for the intercession of my Ummah on the Day of Resurrection.