Payment by Proxy
The Gemora discusses the dispute of Rav Sheishes and Rabbah as to whether a worker can return to his employer when he directed him to a proxy for payment.
The Rishonim discuss the exact parameters of this dispute, and present different options.
1. If the worker explicitly agreed to forgive the employer, regardless of the whether the proxy pays him, all agree that the employer is not liable at all. If the worker conditioned his forgiving the wages on receiving the money from the proxy, all agree that he may return to the employer if the proxy did not pay him. The dispute is in the case where he accepted the arrangement, with no explicit declaration, and the proxy now refuses to pay. Rav Sheishes and Raba dispute whether the proxy has a status of a guarantor or not. Rav Sheishes says that he is a guarantor, and is obligated to pay, and therefore, the worker relied on him, and forgave his employer. Rabbah says that he is not a guarantor, and the worker did not rely on his payment. [Tosfos 112a Chozer, explanation 1]
2. The case in dispute is when the worker agreed to forgive the wages if the proxy pays, but the dispute is whether the worker can claim his wages from the employer before the proxy pays. Rav Sheishes says that as long as the proxy has not refused to pay, the worker's forgiveness is in effect, and he may not return to the employer. [Tosfos, explanation 2, Rosh]
3. Both Rav Sheishes and Rabbah agree that the worker may claim his wages from his employer. The dispute is whether the employer now will transgress bal talin. Rav Sheishes says that once he's removed the bal talin prohibition by directing the worker to the proxy, it may not return, while Rabbah says that bal talin is removed only while the worker is dealing with the proxy, but returns once the worker returns to the employer. [Tosfos, explanation 3]
The Yerushalmi (brought by the Rif and Tosfos) seems to rule like Rav Sheishes, but the Rishonim rule like Rabbah. However, if the employer had a debt owed to him by the proxy, and transferred that debt to the worker in lieu of his wages, the worker now owns the debt through ma'amad shloshton, and no one may back out of the arrangement.
Tosfos learns from the discussion of this case that one need not make a kinyan transaction to effect binding mechilah – forgiveness of a debt.
In all three explanations, the dispute does not relate to whether the worker's forgiveness is valid, but rather the parameters of the forgiveness, or other prohibitions.
Tosfos explains that a pesharah - compromise judgment does need a kinyan, since each side does not know what they are forgiving before, so their forgiveness is akin to a mistaken one, which is not binding without a kinyan.
The Rosh suggests that a kinyan is needed to be able to enforce the pesharah afterwards, not to make the forgiveness binding.
Bal Talin and Contracted Work
The Gemora tied the question of bal talin on contracted work to the question of whether a craftsman owns the improvement of the item.
Tosfos (112a Uman) says that although Rav Sheishes answered that a contracted worker's wages are subject to bal talin, he holds that a craftsman does own the improvement of the item. Rav Sheishes simply meant that some contracted work – e.g., shaking a garment for a set fee per shake – is subject to bal talin.
Extending a Worker's Oath
The Gemora says that if the worker brings witnesses that he claimed his wages at the end of his alloted period, he now has an extension of the period to swear and collect.
Rashi learns that this is a one time extension, for a period of a full day.
The Rambam (Sechirus 11:6) says that this extension can occur multiple times, and each extension is for the next time period – a day or night period – after the claim. See Sma HM 89:13 for an alternate reading of the Rambam.