Rashi on Deuteronomy 12:10/רש"י על דברים י״ב:י׳

1ועברתם את הירדן וישבתם בארץ BUT WHEN YE GO OVER THE JORDAN, AND SETTLE IN THE LAND — This means, that ye shall have divided it amongst the tribes and every man knows his portion and the territory of his tribe,

2והניח לכם AND WHEN HE GIVETH YOU REST — i.e., after having conquered and divided the land and having obtained rest from the nations “which the Lord left by which to prove Israel” (Judges 3:1) — which was only in the days of David (cf. Sifrei Devarim 68:3) — then,