John Gill Commentary Psalms 78:65

"Then the Lord awaked as one out of sleep, Like a mighty man that shouteth by reason of wine." — Psalms 78:65 (ASV)

Then the Lord awaked as one out of sleep
He seemed to be asleep, while he suffered the ark to be taken, and the Israelites to be slain; and he may be said to awake when he exerted his power in smiting the Philistines, and causing their idol to fall before his ark; see (Psalms 7:6) (44:23) ,

and like a mighty man that shouteth by reason of wine ;
who having taken a free draught of generous wine, not to excess, goes forth with great courage and cheerfulness to meet his adversary, shouting as he goes, being sure of victory; which must be applied to God with decency, consistent with the glory of his majesty, and the perfections of his nature; and seems designed to express his power and readiness to help his people, and avenge himself on his enemies; see (Isaiah 42:13) (Zechariah 9:15) .