Deuteronomy 20:7

And what man is there that hath betrothed a wife, and hath not taken her? let him go and return unto his house, lest he die in the battle, and another man take her.

Cross-reference

Deuteronomy 22:23–25 Historical context

Deuteronomy 22:23-25 defines the legal consequences for violating a betrothal, underscoring the seriousness that motivates the exemption here.

Deuteronomy 24:5 extends the exemption to a newly married man for a full year, not just betrothed. Both protect marriage from war's interruption.

Deuteronomy 28:30 threatens the curse of betrothing a wife but another taking her — the very fate the exemption in 20:7 prevents.

Luke 14:18-20 lists the same excuses (field, oxen, wife) for missing a feast, echoing the war exemptions here.