Haggai 2:11

Ask now the priests concerning the law - The priests answer rightly, that, by the law, insulated unholiness spread further than insulated holiness. The flesh of the sacrifice hallowed whatever it should touch, but not further; but the human being, who was defiled by touching a dead body, defiled all he might touch Numbers 19:22. Haggai does not apply the first part; namely, that the worship on the altar which they reared, while they neglected the building of the temple, did not hallow. The possession of a truly tiring does not counterbalance disobedience. Contrariwise, one defilement defiled the whole man and all which he touched, according to that James 2:10, "whosoever shall keep the whole law and yet offend in one point, he is guilty of all."

In the application, the two melt into one, for the holy thing, namely, the altar which they raised out of fear on their return, so far from hallowing the land or people by the sacrifices offered thereon, was itself defiled. "This people" and "this nation" (not "My people") since they in act disowned Him. "Whatever they offer there," i. e., on that altar, instead of the temple which God commanded, is unclean, offending Him who gave all.

2:11 Concerning the law - What the law saith in this case.