Verses with the word eternal in the Old Testament (2 verses):

Deuteronomy 33:27
The eternal God is thy refuge, and underneath are the everlasting arms: and he shall thrust out the enemy from before thee; and shall say, Destroy them.

Isaiah 60:15
Whereas thou has been forsaken and hated, so that no man went through thee, I will make thee an eternal excellency, a joy of many generations.