Albert Barnes Commentary Ezra 10:8

"and that whosoever came not within three days, according to the counsel of the princes and the elders, all his substance should be forfeited, and himself separated from the assembly of the captivity." — Ezra 10:8 (ASV)

Separated from the congregation - that is, “excommunicated” (Numbers 19:20, etc.). The power assigned to Ezra is stated in Ezra 7:25-26.