Sunan of Abu Dawood Book 8, Hadith 1493

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ مَالِكِ بْنِ مِغْوَلٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ بُرَيْدَةَ، عَنْ أَبِيهِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم سَمِعَ رَجُلاً يَقُولُ اللَّهُمَّ إِنِّي أَسْأَلُكَ أَنِّي أَشْهَدُ أَنَّكَ أَنْتَ اللَّهُ لاَ إِلَهَ إِلاَّ أَنْتَ الأَحَدُ الصَّمَدُ الَّذِي لَمْ يَلِدْ وَلَمْ يُولَدْ وَلَمْ يَكُنْ لَهُ كُفُوًا أَحَدٌ ‏.‏ فَقَالَ ‏ "‏ لَقَدْ سَأَلْتَ اللَّهَ بِالاِسْمِ الَّذِي إِذَا سُئِلَ بِهِ أَعْطَى وَإِذَا دُعِيَ بِهِ أَجَابَ ‏"‏ ‏.‏

Narrated Buraydah ibn al-Hasib: The Messenger of Allah (ﷺ) heard a man saying: O Allah, I ask Thee, I bear witness that there is no god but Thou, the One, He to Whom men repair, Who has not begotten, and has not been begotten, and to Whom no one is equal, and he said: You have supplicated Allah using His Greatest Name, when asked with this name He gives, and when supplicated by this name he answers