Mukhtasar Sahih Bukhari — Hadith 2069

Narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Noble Prophet (peace and blessings of Allah be upon him) said: "Every prophet has a supplication that is certainly accepted (whatever he asks, Allah Almighty surely grants it), and I wish to reserve my (such) accepted supplication for intercession for my Ummah in the Hereafter."