Psalm 24

The psalm is written for two choirs and a set of doors. A procession approaches, a challenge is issued, an answer is given, and the doors open. Ancient cities had massive gate complexes — thick timber leaves plated with bronze, set in a chambered stone gateway, barred from inside. "Lift up your heads, O ye gates" addresses the lintel and the doors themselves as though they should stand taller for who is coming.

The ark was a gold-covered chest with carrying poles, and the Law required Levites to bear it on their shoulders. David learned that the hard way — the first attempt to move it on a new cart ended in a man's death at Nachon's threshing floor, and it was three months before he tried again, that time by the book, with sacrifices offered along the route.

The entrance requirements in verses 3–6 belong to the same family as Psalm 15: clean hands, a pure heart, no lifting of the soul to vanity, no swearing deceitfully. Again, what a temple in Egypt or Babylon posted at its door was mostly about ritual state; Israel's list is about conduct and loyalty.

"The Lord strong and mighty, the Lord mighty in battle" and "the Lord of hosts" are military titles. Hosts means armies — the armies of Israel and the armies of heaven both. The ark itself had gone before Israel in war.