'Sack's' in the Bible

And at the lodging place, as one of them opened his sack to feed his donkey, he saw his money in the opening of his sack.

And he commanded the steward of his house, saying, “Fill the men’s sacks with food, as much as they can carry, and put every man’s [grain] money in the mouth of the sack.

Put my [personal] cup, the silver cup, in the mouth of the sack of the youngest, with his grain money.” And the steward did as Joseph had told him.