John Gill Commentary 1 Samuel 8:17

"He will take the tenth of your flocks: and ye shall be his servants." — 1 Samuel 8:17 (ASV)

He will take the tenth of your sheep As well as of their seed and vineyards; and not the tithe of their flocks only, but of their herds also, which are here included, as Kimchi observes:

and you shall be his servants : made slaves of by him, even as the Canaanitish servants were, according to Abarbinel; though others interpret it more mildly of their being obliged to pay tribute and taxes, for the support of his government.