Sayyiduna Abu Hurayrah (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "Allah Almighty will raise a man's rank (on the Day of Resurrection), and that man will say: 'Why is this being given to me?' Allah Almighty will say: 'Because of your child's supplicating for you.'"
Imam al-Bazzar recorded this narration, and its narrators are the narrators of the Sahih, except for Asim bin Bahdalah, and he is hasan al-hadith (fair in hadith). Various routes of this narration have already passed in the Book of Repentance, in the chapter on a child's seeking forgiveness for his father.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدعية / 17240