Deuteronomy 7:3 New English Translation

³You must not intermarry with them. Do not give your daughters^[a] to their sons or take their daughters for your sons,

Deuteronomy 7:3 sn Heb “Do not give your daughter to his son.” The command (beginning at 7:1) is given in the singular form of “you” to emphasize individual responsibility. At this point, the Hebrew also switches from the plural (see previous clause) to the singular in reference to the Canaanite sons and daughters. While the principle applies to everyone in the nation, the rhetorical presentation is of an individual father making a decision about his specific child and a particular potential spouse.

New English Translation (NET)