Verse 20: This we will do to them; we will even let them live, lest (see 2 Sam. 21:1, 2, 6; Ezek. 17:13, 15, 18, 19; Zech. 5:3, 4; Mal. 3:5) wrath be upon us, because of the oath which we sware unto them.
[Let them be spared, that they might live, וְהַחֲיֵה] And by causing to live (Montanus). An infinitive in the place of the future/imperfect of the finite mode (Masius). By causing to live (Septuagint); we will cause to live (Jonathan, similarly Junius and Tremllius). The ו/and ought not to be translated in וְהַחֲיֵה (Vatablus).
[Lest the anger of the Lord, etc.] Even if it was not strictly according to the letter, nevertheless the men, simple and of old-fashioned honesty, although they were not at all judging the point of that sort of law with refinement, but were regarding among themselves the third precept of the Decalogue, not without reason feared the anger of God. From which let us learn that whatever we have promised with such surety (provided it be not contrary to the Law of God), even if we realize that we have been tricked, we should nevertheless fulfill; even if what thence to us happens to be loss, we should rather make it good with other honest reasons than seek some reason for breaking faith (Masius).
 Hebrew: זֹ֛את נַעֲשֶׂ֥ה לָהֶ֖ם וְהַחֲיֵ֣ה אוֹתָ֑ם וְלֹֽא־יִֽהְיֶ֤ה עָלֵ֙ינוּ֙ קֶ֔צֶף עַל־הַשְּׁבוּעָ֖ה אֲשֶׁר־נִשְׁבַּ֥עְנוּ לָהֶֽם׃
 The Hiphil conjugation frequently conveys a causative sense.