What are the connotations of "Ba'aLa'av Imo", which exempts the Shomer from paying?
Rashi: It means that, if the owner is in the Shomer's employ at the time when the loan takes place, 1 or when the Shomer takes possession of the deposit, 2 the latter is Patur 3 - even for negligence (Rosh, Seforno). 4
Rashbam: The owner is working with the animal together with the owner.
Bavaa Metzi'a, 94a: It teches us that, if someone borrows a cow and he 'borrows' or hired its owner together with it, 5 or he 'borrows' or hires the owner and then borrows the cow, and it died, 6 he is Patur.
Bava Metzi'a, 96a: "Be'aLa'av Imo" implies "Be'aLa'av", 've'Lo Shelucho'
Even if he is no longer in his employ when the animal dies or is stolen (Rashi).
Bava Metzi'a, 96a: We actually learn this from "mi'Im Re'eihu" (in Pasuk 13), only were it not for "Be'aLa'av Ein Imo", "ve'Im Be'aLa'av Imo", we would have thought that "me'Im Re'eihu" is a manner of speech.
And even from a Shevu'ah (Yerushalmi, Shevu'os, 8:1
Since (in the previous Pasuk) the Torah wrote "Be'aLa'av Ein Imo, Shalem Yeshalem" why does it see fit to write here "Im Be'aLa'av Imo, Lo Yeshalem"?
Bava Metzi'a, 95b: To teach us that, if the animal left the owner's domain even for a short while together with the owner and died, the Shomer is Patur. 1
Why does 'Be'aLa'av Imo' exempt?
Seforno: Since the owner is so closely associated with the Shomer, we can assume that he gives him the deposit 1 as a gift, on condition that he returns it when he is finished with it.
Moshav Zekenim, citing Ri: Had something happened to the owner at the time, the borrower would be exempt. All the more so he is exempt for his property. His property should not be more stringent than his body!
Sefer ha'Chinuch (Mitzvah 60): If the owner is there and sees, there is no reason to obligate the Shomer. Really, it should depend on being there at the time of the Ones, but the Torah gave a uniform law, that it depends on working for the borrower at the time of the loan.
The Torah was concerned that the employer will be upset that his worker did not believe him, and demanded a Shevu'ah, and he may come to fire him. Therefore, the Torah totally exempts the employer. (Heard from R. Shimon Mussoli and R. Danny Lehman. - PF.)
Seeing as he did not make a specific condition to the contrary (See Seforno).
What is the meaning of "Im Sachir hu, Ba bi'Secharo"?
Rashi, Rashbam and Targum Yonasan: With reference to a Socher (a hirer), the Torah is saying that, since he has to pay for the use of the animal ("Ba bi'Secharo"), he does not enjoy the full benefit of a borrower, and is therefore Patur from Onsin (but is Chayav for Geneivash va'Aveidah