His strength, to wit, the ark, called God's strength, 1 Chronicles 16:11, and the ark of his strength, Psalms 132:8, because it was the sign and pledge of his strength or power put forth on his people's behalf. His glory; so the ark is called, as being the monument and seat of God's glorious presence, and an instrument of his glorious works. The enemy; namely, the Philistines; of which see 1Sa 4.
Related Commentaries of Psalms 78:61
Psalms 78:61
61 And delivered his strength into captivity, and his glory into the enemy's hand.