Who knows the heart of men? The Scriptures say that only God knows the hearts of men...
Yhwh
But the Lord said to Samuel, “Do not look at his appearance or at his physical stature, because I have refused him. For the Lord does not see as man sees; for man looks at the outward appearance, but the Lord [yhwh] looks at the heart.”
~ 1 Sam 16:7
Yet regard the prayer of Your servant and his supplication, O Lord [yhwh] my God [elohim], and listen to the cry and the prayer which Your servant is praying before You: ... then hear from heaven Your dwelling place, and forgive, and give to everyone according to all his ways, whose heart You know (for You alone know the hearts of the sons of men),
~ 2 Ch 6:19,30
I, the Lord [yhwh], search the heart,
I test the mind,
Even to give every man according to his ways,
According to the fruit of his doings.
~ Jer 17:10
Jesus
But Jesus did not commit Himself to them, because He knew all men, and had no need that anyone should testify of man, for He knew what was in man.
~ Jn 2:24,25
“And to the angel of the church in Thyatira write,
‘These things says the Son of God, who has eyes like a flame of fire, and His feet like fine brass: ... I will kill her children with death, and all the churches shall know that I am He who searches the minds and hearts. And I will give to each one of you according to your works.
~ Rev 2:18,23