“I the Lord search the heart and examine the mind, to reward each person according to their conduct, according to what their deeds deserve.”
The Lord searches and examines the mind. He tests the heart. He is giving to each man according to his ways. And, according to the results of his deeds.
He gets to the heart of the human. He gets to the root of things. He treats them as they really are, not as they pretend to be. So let your heart be presentable in His presence, He examines it.