The Meaning of the Hadith "The Two Parties to a Sale Have the Option"

Question:
Is it a condition that the money be received, or if one says, for example, "I will give you the money tomorrow," and they part ways, does the sale take place without the money being received?

Answer:
It varies: if it involves riba, the sale is not completed; if it does not involve riba, the sale is completed. So if one says, "The sale is concluded between us for a car, or a book, or a garment, or something similar," and they part ways, the sale is completed, and the price is due at the deferred time.
Q: If he returns, does the seller sin?
A: No, if they part ways, the sale is binding, unless they are lenient and agree to cancel it; there is no objection, the right is theirs.