Source and decoding
לא קשיא: כאן בשטר הלואה, דלא יהיב אינש זוזי בכדי. כאן במקח וממכר, דעביד אינש דזבין ארעא ליומיה.
There is no difficulty: Here it concerns a loan document, since a person does not give money for nothing; there it concerns a sale, since a person may buy land even for a single day.
Shmuel distinguishes loan from sale when warranty is omitted. For a loan it can be a scribal omission; a buyer may accept sale risk. This clarifies his position here, not every authority’s ruling. Define warranty and test transactional assumptions.