Numbers 5:13 (BSB)

by sleeping with another man, and it is concealed from her husband and her impurity is undetected (since there is no witness against her and she was not caught in the act),

From Numbers 5. Also in the ESV.

Commentary on Numbers 5:13

• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on Numbers 5:11-31: We have here the law concerning the solemn trial of a wife whose husband was jealous of her. Observe, I. What was the case supposed: That a man had some reason to suspect his wife to have committed adultery, Num 5:12-14. Here, 1. The sin of adultery is justly represented as an exceedingly sinful sin; it is going aside from God and virtue, and the good way, Pro 2:17.
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on Numbers 5:13: And a man lie with her carnally,.... That is, is suspected that he has so done, not that it is a clear case, for it follows: and it be hid from the eyes of her husband, and be kept close; so that it is not known by her husband, nor by any other; "she hath hid herself", so Ainsworth, being in a private place with...
• Keil & Delitzsch (Lutheran), Biblical Commentary on the Old Testament on Numbers 5:11-31: Num 5:11-31 Sentence of God upon Wives Suspected of Adultery. - As any suspicion cherished by a man against his wife, that she either is or has been guilty of adultery, whether well-founded or not, is sufficient to shake the marriage connection to its very roots, and to undermine, along with marriage, the foundation of the civil commonwealth, it was of the greatest importance to...