Tafsir of Al-A'raf 7:151

he (Musa) said , "O my Lord! Forgive me and my brother, and admit us into Your mercy, for you are the Most Merciful of those who show mercy.'' Ibn Abi Hatim recorded that Ibn Abbas said that the Messenger of Allah said,

يرحم الله موسى ليس المعاين كالمخبر أخبره ربه عز وجل أن قومه فتنوا بعده فلم يلق اﻻلواح فلما رآهم وعاينهم ألقى اﻻلواح

May Allah grant His mercy to Musa! Surely, he who observes (something) is nothing like he who is informed about it. His Lord, the Exalted and Most Honored, told him that his people were tested after him, but he did not throw the Tablets. When he saw them with his eyes, then he threw the Tablets