Sahih al-Bukhari 6304
Sahih al-Bukhari · Book 80: Invocations · For every Prophet there is one invocation surely granted
Narrated Abu Huraira:
حَدَّثَنَا إِسْمَاعِيلُ ، قَالَ حَدَّثَنِي مَالِكٌ ، عَنْ أَبِي الزِّنَادِ ، عَنِ الأَعْرَجِ ، عَنْ أَبِي هُرَيْرَةَ ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " لِكُلِّ نَبِيٍّ دَعْوَةٌ مُسْتَجَابَةٌ يَدْعُو بِهَا، وَأُرِيدُ أَنْ أَخْتَبِئَ دَعْوَتِي شَفَاعَةً لأُمَّتِي فِي الآخِرَةِ " .
Allah's Messenger (ﷺ) said, "For every prophet there is one (special invocation (that will not be rejected) with which he appeals (to Allah), and I want to keep such an invocation for interceding for my followers in the Hereafter."