The Messenger of Allah ﷺ said, "Allah raises the rank of the righteous servant in Paradise, and he asks, 'My Lord, how have I attained this?' Allah replies, 'Through your child's seeking forgiveness for you.'"In another wording, "Through your child's supplication for you."
قال رسول الله ﷺ: إن الله عز وجل ليرفع الدرجة للعبد الصالح في الجنة فيقول: يا رب، أنى لي هذه؟ فيقول: باستغفار ولدك لك وفي لفظ: بدعاء ولدك لك
Ibn Majah (3660), Ahmad (10610), and Bazzar (9024) all narrated it through Hammad bin Salama, from Asim bin Abu Najud, from Abu Salih, from Abu Hurairah, who mentioned it. The wording is Ahmad's, and the second version is Bazzar's. Its chain is hasan because of Asim bin Abu Najud, for his hadith is hasan.