Marriage: Expressed by Giving Daughters to Sons, and Sons to Daughters
Source: TTT
Deuteronomy 7:3
Do not intermarry with them. Do not give your daughters to their sons or take their daughters for your sons,
Ezra 9:12
Now, therefore, do not give your daughters in marriage to their sons or take their daughters for your sons. Never seek their peace or prosperity, so that you may be strong and may eat the good things of the land, leaving it as an inheritance to your sons forever.’