Charles Ellicott Commentary 1 Chronicles 29:20

"And David said to all the assembly, Now bless Jehovah your God. And all the assembly blessed Jehovah, the God of their fathers, and bowed down their heads, and worshipped Jehovah, and the king." — 1 Chronicles 29:20 (ASV)

Now bless. — Bless you, I pray. The “now” is not a note of time, but of entreaty.

Blessed the Lord God of their fathers. —Probably using a liturgical formula, like the doxologies that close the books of the Psalter (Psalms 41:13; Psalms 72:18–19; Psalms 89:52, etc.).

And bowed down their heads. —Or, and bowed. Vulgate, inclinaverunt se; Septuagint here, κάμψαντες τὰ γόνατα, bending the knees; but usually κνψαντες, stooping, bowing.

Worshipped. —Prostrated themselves. Septuagint, προσεκύνησαν. The two expressions “bowed and worshipped” are always united, as here (except in 2 Chronicles 20:18. Compare Genesis 24:26; Exodus 12:27). The Syriac renders, “fell down and worshipped.”

And the king. —As God’s earthly representative, David receives the same tokens of reverence and homage. (Compare 1 Kings 1:31.)