Exodus 7:14

And the Lord said unto Moses, Pharaoh's heart is hardened,.... Or "heavy" c, dull and stupid, stiff and inflexible, cannot lift up his heart, or find in his heart to obey the will of God:

he refuseth to let the people go; which was an instance and proof of the hardness and heaviness of his heart, on which the above miracle had made no impression, to regard what God by his ambassadors had required of him.

c כבד "grave", Montanus, Drusius. So Ainsworth.