Not as a result of their own prowess

The people of Israel did not obtain the soil of this state, which his to be founded upon the Law of God, as a result of their own prowess. The soil was entrusted to them by God solely because they subordinated themselves obediently to His will.

This loyal obedience toward the Law of God will also be the only means of ensuring their material prosperity in the land. This thought is expressed, again and again, in terms of both the nation and its individual members, by the pilgrimages in the spring, summer and fall, and by Israel’s act of laying its first fruits at the feet of this Law.

Therefore, the people of Israel must not permit their contacts with the previous occupants of the land (which will be ceded to them only little by little) to delude them into the heathen notion, diametrically opposed to Judaism, that material prosperity is not dependent upon observance of the laws of morality, and that the forces of nature must be worshiped as sources of material prosperity. 

R' Samson Raphael Hirsch, , the Pentateuch, Shemos 23:20