Adam Clarke on Numbers 5:29

This is the law of jealousies - And this is the most singular law in the whole Pentateuch: a law that seems to have been copied by almost all the nations of the earth, whether civilized or barbarian, as we find that similar modes of trial for suspected offenses were used when complete evidence was wanting to convict; and where it was expected that the object of their worship would interfere for the sake of justice, in order that the guilty should be brought to punishment, and the innocent be cleared. For general information on this head see at the end of this chapter. (See Num 5:31 (note)).