John Gill Commentary 2 Chronicles 29:33

"And the consecrated things were six hundred oxen and three thousand sheep." — 2 Chronicles 29:33 (ASV)

And the consecrated things
Which were devoted for peace offerings, of which the owners had a part: were six hundred oxen, and three thousand sheep; which was a much lesser number than what were offered upon occasion in the times of David and Solomon, the nation being poorer.

And besides, these were only the oblation of two tribes, they of all Israel.