This Bible contradiction is from the Skeptic's Annotated Bible.
God never sleeps.
Psalm 121:3-4 View context
He will not suffer thy foot to be moved: he that keepeth thee will not slumber.
Behold, he that keepeth Israel shall neither slumber nor sleep.
God sometimes sleeps.
Psalm 44:23 View context
Awake, why sleepest thou, O Lord? arise, cast [us] not off for ever.