• Is חליפין performed with כליו של מקנה or של קונה?

The Gemara asks whose utensil is used to perform a קנין חליפין. Rav says: בכליו של קונה – it is performed with the utensil of the one acquiring the item, by giving his kerchief (for example) to the item’s current owner, because the one acquiring wants the מקנה to acquire his kerchief so he should transfer the item to him. Levi says: בכליו של מקנה – it is performed with the utensil of the one transferring the item, by giving his kerchief to the one acquiring the item. Rava clarifies that it is not the transfer of the kerchief itself that transfers land together with it (as a reverse form of kinyan agav); rather, בההיא הנאה דקא מקבל מיניה – in exchange for the benefit the giver receives that [the recipient] accepts the kerchief from him as a gift, גמר ואקני ליה – [the giver] decides to transfer the land to him. This depends on a machlokes Tannaim about the passuk: שלף איש נעלו ונתן לרעהו – a man would remove his shoe and give it to his fellow to effect חליפין. The Tanna Kamma explains that Boaz, who was acquiring the right to redeem the land of Naami and Rus, gave his shoe to the “redeemer” (their closest relative), and Rebbe Yehudah says the redeemer gave his shoe to Boaz.

• If a כלי is to effect חליפין

A Baraisa states: קונין בכלי – one may acquire with a utensil for חליפין, אף על פי שאין בו שוה פרוטה – even though it is not worth a perutah. Rav Nachman says a utensil is required for חליפין but produce (or any other non-utensil) cannot effect חליפין, because the passuk says "נעלו" – his shoe, teaching: נעל אין – with a shoe (or something similar), yes, חליפין would take effect, מידי אחרינא לא – but with something else, it would not. Rav Sheishess says even produce may be used for חליפין, and darshens the phrase "לקים כל דבר" – to confirm anything, to allow a kinyan with anything. Rav Nachman explains this phrase to teach that one can acquire anything via a shoe (i.e., חליפין). Rav Sheishess explains that the word "נעל" teaches that it must be similar to a shoe in being דבר המסויים – a whole thing, excluding partial items, such as half a pomegranate or half a walnut. Rav Shisha the son of Rav Idi notes that the current text for a contract for a קנין סודר, which includes the word "במנא" – with a utensil, follows Rav Nachman’s opinion.

• Machlokes if משיכה acquires מדאורייתא or מדרבנן

The Mishnah on Daf 44a taught that the acquiring of the merchandise, and not the money, finalizes a sale. Rebbe Yochanan says: דבר תורה מעות קונות – According to Torah law, money acquires מטלטלין. The reason the Rabbis said that משיכה, and not money, acquires מטלטלין, is: גזירה שמא יאמר לו נשרפו חטיך בעלייה - a Rabbinic decree, because [the seller] might tell him, “Your wheat was burned in the attic!” Since the wheat, which is still in the seller’s possession, now belongs to the buyer owns, the seller has no incentive to protect it from accidental damage. They decreed that the buyer could retract from the sale until he acquires it, so the seller would labor to save it from harm. Reish Lakish says: משיכה מפורשת מן התורה – the kinyan of משיכה is taught explicitly by the Torah, because the phrase "או קנה מיד עמיתך" – or buy from your fellow’s hand, refers to: דבר הנקנה מיד ליד – something bought by passing it from hand to hand. The Gemara proves that Rebbe Shimon holds like Rebbe Yochanan.

Siman – Maze. The person running through the Kinyan Maze who decided to go down the path of the קונה holding the kerchief instead of the מקנה holding the kerchief, and then ran past and ignored an ear of corn and found a shoe to do חליפין with instead, was racing against the clock to acquire a bushel of wheat with משיכה before the seller could tell him, “Your wheat was burned in the attic.”