Or HaChaim on Deuteronomy 26:3/אור החיים על דברים כ״ו:ג׳

1 אשר נשבע ה׳ לאבותינו, "which the Lord swore to our forefathers to give to us." The wording of this verse excludes this passage being recited by proselytes. He is obligated to bring the offering but cannot recite a line which would make a liar out of him (compare Bikkurim chapter 1).