Numbers 25:4 - Joseph Benson’s Commentary on the Old and New Testaments

Take That is, apprehend; all the heads (or chief) of the people Such as were chief in this transgression, and in place and power. These are singled out to this exemplary punishment for their concurrence with others in this wickedness, which was more odious, and of more pernicious tendency in them. Hang them up before the Lord That is, either before the sanctuary, as men who had forsaken the worship of God, and were by his sentence adjudged to die; or, to the vindication of his honour and justice. Others interpret the words thus: Take unto thee, or to thine assistance, the heads, or judges of the people, and hang them up; that is, hang up such as have joined themselves to Baal-peor. This interpretation seems to be justified by the next verse, in which Moses directs the judges to do their duty by punishing the offenders. Against the sun Publicly and openly, as their sin was public and scandalous, that all the people might see, and fear to sin; and speedily, before the sun went down. It was provided by the Jewish law, that the bodies of malefactors should hang no longer than till the evening of the day on which they suffered, Deuteronomy 21:22-23.