Ephesians 1:13

Ephesians 1:13. Ye were sealed— In Rev 7:3 mention is made of God sealing the foreheads of his servants, that they might be known to be his; alluding to the custom of marking the foreheads of slaves, that the public might know that they were the private property of the purchasers. So St. Paul here says, that God sealed with his Spirit those who believed in him, to mark them for his own. See 2 Timothy 2:19.