ASV

then hear thou from heaven thy dwelling-place, and forgive, and render unto every man according to all his ways, whose heart thou knowest (for thou, even thou only, knowest the hearts of the children of men);

KJV

Then hear thou from heaven thy dwelling place, and forgive, and render unto every man according unto all his ways, whose heart thou knowest; (for thou only knowest the hearts of the children of men:)