'Loins' in the Bible

All the persons who came from the loins of Jacob were seventy in number, but Joseph was already in Egypt.

Now you shall eat it in this manner: with your loins girded, your sandals on your feet, and your staff in your hand; and you shall eat it in haste—it is the Lord’s Passover.

You shall make for them linen breeches to cover their bare flesh; they shall reach from the loins even to the thighs.