So I took the evidence of the purchase
The deed of purchase, the book or bill of sale, the instrument of the bargain, as before mentioned: [both] that which is sealed, [according] to the law and custom;
which was both sealed by the buyer and seller, and was sealed up, and not to be looked into by everyone, only when there might be a necessity; this was the original copy: and that which was open;
the counter part or copy of the former, which though signed and sealed as the other, yet not sealed up, but was open and exposed to view; either for the relations to see what was done, as some; or for the judges, as others, to ratify and make authentic: or, as is most probable, this copy was laid up in some public register, to have recourse unto upon any occasion; however it was, it was according to the laws and customs of those times, which Jeremiah carefully attended to: or, as others, it lay open for the witnesses to sign; so there are three distinct things; first the written contract; then that as signed and sealed by buyer and seller, according to law; and then as signed, but not sealed, by the witnesses.
The Brenton translation of the Septuagint is in the public domain.