Deuteronomy 33:21

21 The people of Gad took the best land for themselves; a leader’s share was assigned to them. When the leaders of the people were assembled, they carried out the LORD ’s justice and obeyed his regulations for Israel.”

Deuteronomy 33:21 Meaning and Commentary

Deuteronomy 33:21

And he provided a first part for himself
That is, the portion of the land of Sihon and Og, as Jarchi rightly interprets it; which was the beginning or firstfruits of the subduing of the land that was promised; this he looked at, chose, and desired it as his inheritance, ( Numbers 32:1 Numbers 32:2 ) ;

because there, [in] a portion of the lawgiver, [was he] seated;
or in the portion and part of the inheritance of Israel was he placed by Moses the lawgiver, according to the will of God; or because there were in it palaces and towers of great personages, lawgivers, kings, and princes, well covered and strongly fortified; or here he was "hid", or "protected", i.e. their families, wives, and children, while they assisted their brethren in subduing Canaan:

and he came with the heads of the people;
either "to" them, to Moses, Eleazar, and the seventy elders, and the heads of the tribes of Israel, to ask leave to have his part and portion on the other side Jordan, or "with" them, as we supply it; came with them over Jordan armed, to assist in the conquest and subduing of the land of Canaan:

he executed the justice of the Lord, and his judgments with Israel;
that is, either he justly and truly fulfilled all his promises and engagements, on condition of which he was placed on the other side; or he, together with the rest of the Israelites, executed the righteous judgment of God upon the Canaanites, in the expulsion and destruction of them.

Deuteronomy 33:21 In-Context

19 They summon the people to the mountain to offer proper sacrifices there. They benefit from the riches of the sea and the hidden treasures in the sand.”

20 Moses said this about the tribe of Gad: “Blessed is the one who enlarges Gad’s territory! Gad is poised there like a lion to tear off an arm or a head.

21 The people of Gad took the best land for themselves; a leader’s share was assigned to them. When the leaders of the people were assembled, they carried out the LORD ’s justice and obeyed his regulations for Israel.”

22 Moses said this about the tribe of Dan: “Dan is a lion’s cub, leaping out from Bashan.”

23 Moses said this about the tribe of Naphtali: “O Naphtali, you are rich in favor and full of the LORD ’s blessings; may you possess the west and the south.”