The Priest Now Charges Her With an Oath to Speak Truly (Numbers 5:19-20).
‘And the priest shall cause her to swear, and shall say to the woman, If no man has lain with you, and if you have not gone aside to uncleanness, being under your husband, be you free from this water of bitterness which causes the curse. But if you have gone aside, being under your husband, and if you are defiled, and some man has lain with you apart from your husband ---.'
The procedure is now described. First the priest required her to swear, probably to her innocence. This would be the first test as to whether she was guilty or not. Standing there before Yahweh, with the priest solemnly holding the water of bitterness before her, and the barley grain offering in her hand and her hair hanging loose she would be a brazen woman indeed who could swear a false oath knowing that God would shortly bring judgment on her. This first procedure brings out that there was a genuine hope of proving her innocence. After all she had presumably either been protesting that she was innocent, or was, either through confusion, pride or guilt, saying nothing.
Then the priest would say, “If no man has lain with you, and if you have not gone aside to uncleanness, being under your husband, be you free from this water of bitterness which causes the curse. But if you have gone aside, being under your husband, and if you are defiled, and some man has lain with you apart from your husband ---.' Note the charge. As one who is under her husband as his helpmeet, had she been faithful to him or not? If she had she would get away scot free. The water would not bring the curse on her. But if she had not been faithful she was defiled, and was therefore defiling the camp. Note how the charge was left hanging in the air awaiting the second oath. It was to be continued once she had sworn the second oath, the oath of cursing.