Charles Ellicott Commentary Ezra 6:17

"And they offered at the dedication of this house of God a hundred bullocks, two hundred rams, four hundred lambs; and for a sin-offering for all Israel, twelve he-goats, according to the number of the tribes of Israel." — Ezra 6:17 (ASV)

Twelve he goats. —The people are not now “Judah” or “Judah and Benjamin,” but “all Israel.” On the Day of Atonement, on the new moons, and on all the great feasts the kid was the sin offering for the people. But only here is one offered for each tribe.