Sahih Muslim 487
The Book of Faith
حَدَّثَنِي يُونُسُ بْنُ عَبْدِ الأَعْلَى، أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ وَهْبٍ، قَالَ أَخْبَرَنِي مَالِكُ بْنُ أَنَسٍ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي سَلَمَةَ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لِكُلِّ نَبِيٍّ دَعْوَةٌ يَدْعُوهَا فَأُرِيدُ أَنْ أَخْتَبِئَ دَعْوَتِي شَفَاعَةً لأُمَّتِي يَوْمَ الْقِيَامَةِ " .
Abu Huraira reported:Verity the Messenger of Allah (ﷺ) said: There is for every apostle a (special) prayer with which he would pray. I wish I could reserve, my prayer for intercession of my Ummah on the Day of Resurrection
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.