Musannaf Ibn Abi Shaybah 32424 — Book of Faith

Sayyiduna Anas (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) would often make this supplication: "O Turner of hearts, make my heart firm upon Your religion." The Companions (may Allah be pleased with them) said: "O Messenger of Allah (peace and blessings be upon him)! We have believed in you and in the religion you have brought. Do you still fear for us?" He (peace and blessings be upon him) said: "Yes! Indeed, all hearts are between two of the fingers of Allah, and He keeps turning them."