What does 1 Samuel 8:17 mean?

Samuel is coming to the end of his disclaimer about what Israel should expect from their human kings (1 Samuel 8:4–9) to take from them. Neither Samuel nor the Lord is it is morally right for a government to confiscate the children and property of citizens. They are simply pointing out the fact that this is what kings do. God established human government for a reason (Romans 13:1–7), but that does not make it the best solution to any problem.

Israel should also expect the king to take a portion of their livestock for himself. Finally, at the root of this relationship, the people should think of themselves as the king's slaves. Some kings, like Solomon, were careful to distinguish between his "servants" and "slaves" (1 Kings 9:22), but in either cases the people had no choice about whether or not to serve. Ancient kings had the right and the power to command anyone to do whatever he wanted whenever he wanted them to do it. The difference between slave and servant could become a very slim margin, especially if the king was not a righteous and fair leader (Proverbs 29:14).