Deuteronomy 24:5

“When a man hath taken a new wife, etc.] A wife he has lately married, new to him, though a widow, as Jarchi observes; but the Targum of Jonathan says a virgin; however this is opposed to his old wife, and divorced; for this, as Jarchi and Ben Melech say, excepts the return of a divorced wife, who cannot be said to be a new one: he shall not go out to war; this is to be understood of a man that had not only betrothed, but married a wife; a man that had betrothed a wife, and not married her, who went out to war, might return if he would, (<052007>Deuteronomy 20:7); but one that had married a wife was not to go out to war: neither shall be charged with any business; as betrothed ones were;…”

“When a man hath taken a new wife, he shall not go out to war--This law of exemption was founded on good policy and was favorable to matrimony, as it afforded a full opportunity for the affections of the newly married pair being more firmly rooted, and it diminished or removed occasions for the divorces just mentioned.”

“Business - Any publick office or employment, which may cause an absence from or neglect of his wife. One year - That their affections may be firmly settled, so as there may be no occasions for the divorces last mentioned. Deuteronomy 24:6”

“a man: Deu 20:7; Gen 2:24; Mat 19:4-6; Mar 10:6-9; Co1 7:10-15; Eph 5:28, Eph 5:29; Tit 2:4, Tit 2:5 neither: etc. Heb. not anything shall pass upon him cheer up: Pro 5:18; Ecc 9:9; Co1 7:29 Deuteronomy 24:6”