C. F. Keil and Franz Delitzsch on Deuteronomy 15:3

Deu 15:3

The foreigner thou mayest press, but what thou hast with thy brother shall thy hand let go. נכרי is a stranger of another nation, standing in no inward relation to Israel at all, and is to be distinguished from גּר, the foreigner who lived among the Israelites, who had a claim upon their protection and pity. This rule breathes no hatred of foreigners, but simply allows the Israelites the right of every creditor to demand his debts, and enforce the demand upon foreigners, even in the sabbatical year. There was no severity in this, because foreigners could get their ordinary income in the seventh year as well as in any other.