'Stamped' in the Bible

For thus says the Lord of hosts, the God of Israel:“The daughter of Babylon is like a threshing floorAt the time it is stamped firm;Yet in a little while the time of harvest will come for her.”

So I took the paper witnessing the business, one copy rolled up and stamped, and one copy open:

This is what the Lord of armies, the God of Israel, has said: Take these papers, the witness of this business, the one which is rolled up and stamped, and the one which is open; and put them in a vessel of earth so that they may be kept for a long time.