Verses with the word betroth in the Old Testament (3 verses):

Deuteronomy 28:30
Thou shalt betroth a wife, and another man shall lie with her: thou shalt build an house, and thou shalt not dwell therein: thou shalt plant a vineyard, and shalt not gather the grapes thereof.

Hosea 2:19
And I will betroth thee unto me for ever; yea, I will betroth thee unto me in righteousness, and in judgment, and in lovingkindness, and in mercies.

Hosea 2:20
I will even betroth thee unto me in faithfulness: and thou shalt know the LORD.