Cross reference
Matthew 24:41
41 two women grinding at the mill, one will be taken and one will be left.
Exodus 11:5
5 and all the firstborn in the land of Egypt shall die, from the firstborn of Pharaoh who sits on his throne, even to the firstborn of the maid-servant who is behind the mill; and all the firstborn of cattle.
Isaiah 47:2
2 Take the millstones, and grind meal; remove your veil, strip off the train, uncover the leg, pass through the rivers.
Luke 17:35
35 There will be two grinding grain together. One will be taken, and the other will be left."