Nawas bin Saman reported,

I heard the Messenger of Allah ﷺ say, "There is no heart that is not between two of the fingers of the Lord of the Worlds. If He wills to keep it upright, He keeps it upright, and if He wills to make it deviate, He makes it deviate."He used to say, "Turner of hearts, make our hearts firm upon Your religion. The scale is in the hand of the Most Merciful عز وجل, He lowers it and raises it."

Azami 12066

Sahih

عن النواس بن سمعان الكلابي يقول

سمعت رسول الله ﷺ يقول: ما من قلب إلا وهو بين أصبعين من أصابع رب العالمين، إن شاء أن يقيمه أقامه، وإن شاء أن يزيغه أزاغه، وكان يقول: يا مقلب القلوب ثبت قلوبنا على دينك، والميزان بيد الرحمن عز وجل يخفضه ويرفعه.

الأعظمي 12066صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Tafsir of the great Quran
Chapter
Virtues of Surah Baqarah
Section
His saying, "Our Lord, do not let our hearts deviate after You have guided us, and grant us mercy from Yourself. Indeed, You are the Bestower."
Numbering
Jami al-Kamil 12066 (2nd edition)
Azami 12066