Yosef Karo, Shulchan Aruch — Choshen Mishpat 39…
“ When someone lends another money with a written deed, he may collect from the borrower's real estate, even if the deed does not specifically mention a lien, since we rule that [omission of mention of] a lien is considered to have been a mistake on the part of the writer of the deed. If there are witnesses that the loan was effected with a "kinyan sudar", then even without a deed the lender may collect from the borrower's real estate. ”
