I came in upon the Prophet ﷺ while he was praying. He had placed his left hand on his left thigh and his right hand on his right thigh, with his fingers closed and his index finger extended, and he was saying, "Turner of hearts, keep my heart firm upon Your religion."
دخلت على النبي ﷺ وهو يصلي، وقد وضع يده اليسرى على فخذه اليسرى، ووضع يده اليمنى على فخذه اليمنى، وقبض أصابعه، وبسط السبابة وهو يقول: يا مقلب القلوب، ثبت قلبي على دينك.
Tirmidhi (3587) narrated it from Uqba bin Mukram, who said, Saeed bin Sufyan Jahdari told us, Abdullah bin Madan told us, Asim bin Kulayb Jarmi told me, from his father, from his grandfather, who said, and he mentioned it. It is a hasan hadith by this route, as noted in the book of prayer.