John Gill Commentary Deuteronomy 28:44

"He shall lend to thee, and thou shalt not lend to him: he shall be the head, and thou shalt be the tail." — Deuteronomy 28:44 (ASV)

He shall lend to you, and you shall not lend to him
The stranger, or one of another nation, shall be in a capacity of lending to the Jew, when the Jew would not be able to lend to the Gentile, his circumstances being so low and mean; to show which is the design of the expression, and not the kindness or unkindness of either; see (Deuteronomy 28:12) ;

he shall be the head, and you shall be the tail ;
he shall be ruler and governor, and you shall be subject to him; see (Deuteronomy 28:13) .