Sahih Muslim 201
Sahih Muslim · Book 1: The Book of Faith · The Prophet (saws) will defer his supplication in order to intercede for his ummah
Abu Zubair heard Jabir b. Abdullah reporting it from the Messenger of Allah (ﷺ):
وَحَدَّثَنِي مُحَمَّدُ بْنُ أَحْمَدَ بْنِ أَبِي خَلَفٍ ، حَدَّثَنَا رَوْحٌ ، حَدَّثَنَا ابْنُ جُرَيْجٍ ، قَالَ أَخْبَرَنِي أَبُو الزُّبَيْرِ ، أَنَّهُ سَمِعَ جَابِرَ بْنَ عَبْدِ اللَّهِ ، يَقُولُ عَنِ النَّبِيِّ صلى الله عليه وسلم " لِكُلِّ نَبِيٍّ دَعْوَةٌ قَدْ دَعَا بِهَا فِي أُمَّتِهِ وَخَبَأْتُ دَعْوَتِي شَفَاعَةً لأُمَّتِي يَوْمَ الْقِيَامَةِ " .
For every apostle was a prayer with which he prayed (to his Lord) for his Ummah, but I have reserved my prayer for the intercession of my Ummah on the Day of Resurrection.