Abu Hurairah reported,
The Messenger of Allah ﷺ said, "Allah 
raises the rank of the righteous servant in Paradise, and the servant says, 'My Lord, how did I attain this?' Allah replies, 'Through your child's seeking forgiveness for you.'"In another wording, "Through your child's supplication for you."
Azami 10949
Hasanعن أبي هريرة قال
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 said what has already been mentioned. The wording given is that of Ahmad, while the second version is that of Bazzar. Its chain of transmission is hasan because of Asim bin Abu Najud, for his hadith is hasan.