Strong’s Greek
G2589 — kardiognostes
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
καρδιογνώστης
kardiognostes — pronounced kar-dee-og-noce'-tace
from 2588 and 1097; a heart-knower:--which knowest the hearts. see GREEK for 2588 see GREEK for 1097
2 occurrences in the KJV.
Acts 1:24
And they prayed, and said, Thou, Lord, which knowest the hearts of all men, shew whether of these two thou hast chosen,
Acts 15:8
And God, which knoweth the hearts, bare them witness, giving them the Holy Ghost, even as he did unto us;