Jeremiah 29:6

take ye wives and beget sons and daughters, thereby establishing families; and take wives for your sons and give your daughters to husbands, for the giving in marriage is essentially a function of the parents, a duty which they dared not disregard, that they may bear sons and daughters, that ye may be increased there and not diminished, for the nation was not to die out during the period of the Babylonian Exile.