Charles Spurgeon Commentary Deuteronomy 15:4

"Howbeit there shall be no poor with thee; (for Jehovah will surely bless thee in the land which Jehovah thy God giveth thee for an inheritance to possess it;)" — Deuteronomy 15:4 (ASV)

Save when there shall be no poor among you;

If there were no poor, then there would be no need for this law.