Numbers 25:4

And the LORD said unto Moses, Take all the heads of the people, and hang them up before the LORD against the sun, that the fierce anger of the LORD may be turned away from Israel.

Take all the heads of the people, and hang them up. The language is somewhat ambiguous, and may mean either that Moses was to take measures, with the help of "all the heads" - i:e., the judges (Numbers 25:5) - for putting to death the most noted and flagrant offenders in each of the tribes; or that the persons here ordered for execution were the officers-subordinate, but still public officers-rulers of tens and hundreds, who might have been concerned in the infamous deeds at Peor, and who, as from their dignity and power they ought to have preserved the people in their integrity, were to be consigned to a violent and ignominious death as a public warning. Israelite criminals who were condemned to capital punishment were first stoned or slain, and then gibbeted.

Before the Lord - i:e., for vindicating the honour of the true God and the fundamental principle of the national covenant.

Against the sun - i:e., as a mark of public ignominy; but they were to be removed toward sunset (Deuteronomy 21:23).