Numbers 13:27-28

13:27 They told Moses, “We went to the land where you sent us. It is indeed flowing with milk and honey, and this is its fruit. 13:28 But the inhabitants are strong, and the cities are fortified and very large. Moreover we saw the descendants of Anak there.

Deuteronomy 3:5

3:5 All of these cities were fortified by high walls, gates, and locking bars; in addition there were a great many open villages.

Deuteronomy 6:10-12

Exhortation to Worship the Lord Exclusively

6:10 Then when the Lord your God brings you to the land he promised your ancestors Abraham, Isaac, and Jacob to give you – a land with large, fine cities you did not build, 6:11 houses filled with choice things you did not accumulate, hewn out cisterns you did not dig, and vineyards and olive groves you did not plant – and you eat your fill, 6:12 be careful not to forget the Lord who brought you out of Egypt, that place of slavery.

Deuteronomy 9:1-3

Theological Justification of the Conquest

9:1 Listen, Israel: Today you are about to cross the Jordan so you can dispossess the nations there, people greater and stronger than you who live in large cities with extremely high fortifications. 9:2 They include the Anakites, a numerous and tall people whom you know about and of whom it is said, “Who is able to resist the Anakites?” 9:3 Understand today that the Lord your God who goes before you is a devouring fire; he will defeat and subdue them before you. You will dispossess and destroy them quickly just as he has told you.