Numbers 31:18 YLT

¹⁶  lo, they -- they have been to the sons of Israel, through the word of Balaam, to cause a trespass against Jehovah in the matter of Peor, and the plague is in the company of Jehovah.

¹⁷  'And now, slay ye every male among the infants, yea, every woman known of man by the lying of a male ye have slain;

¹⁸  and all the infants among the women, who have not known the lying of a male, ye have kept alive for yourselves.

¹⁹  'And ye, encamp ye at the outside of the camp seven days -- any who hath slain a person, and any who hath come against a pierced one, ye cleanse yourselves on the third day, and on the seventh day -- ye and your captives;

²⁰  and every garment, and every skin vessel, and every work of goats' 'hair', and every wooden vessel, ye yourselves cleanse.'