פירוש על מעילה 6:4

שניהם מעלו – as long as that Etrog/citron would be worth two pennies like the houseowner gave him. The houseowner committed sacrilege since the agent purchased for him according to what he said and worth as he gave him, he thusly performed his agency, but the agent committed a misappropriation for he purchased of his own intention a pomegranate with a penny that was not in the agency of the houseowner.

If he gave him two perutahs and said, “Bring me for them an etrog,” and he brought for one perutah an etrog and for the other a pomegranate, both are guilty of sacrilege. Rabbi Judah says: the employer is not guilty of sacrilege for he could say, “I wanted a large etrog and you brought me a small and bad one.” According to the first opinion, the employer is guilty of sacrilege with one of the perutahs, because the agent did perform the instructions to buy an etrog. The agent is guilty of sacrilege with the other perutah because he changed the instructions and bought a pomegranate with the other perutah. Rabbi Judah argues that the employer is not guilty at all, because he can claim that he wanted a two-perutah etrog, not a one-perutah etrog. Therefore, we don’t consider the agent as having fulfilled half of his instructions; rather he has not fulfilled the instructions at all and he alone is guilty of sacrilege.

ר' יהודה אומר בעה"ב לא מעל – for he (i.e., the houseowner) said to the agent, If you would purchase an Etrog/citron for two pennies like I gave to you, you would bring me a large Etrog/citron worth four pennies, [but] now that you didn’t give other than a penny, you brought me an Etrog/citron worth two pennies which is a small and bad, it is found that you did not perform my agency. But the Halakha is not according to Rabbi Yehuda.

If he gave him a golden denar and said to him, “Bring me a shirt,” and he brought him for three [silver selas] a shirt and for the other three a cloak, both are guilty of sacrilege. Rabbi Judah says: the employer is not guilty of sacrilege, for he can argue, “I wanted a large shirt and you brought me a small and bad one.” The employer sends him with a golden denar to buy a shirt. A golden denar is worth 25 silver denars, or 6.5 silver selas. The agent uses half of the money to buy the cloak, and the other half to buy a shirt. As in the previous section, the first opinion considers them both to have committed sacrilege. The employer committed sacrilege with the first half of the money, and the agent by changing the instructions with the second half. Again, Rabbi Judah argues that only the agent committed sacrilege. The employer sent him to buy a golden denar shirt (Gucci?) and not a cheaper one (Target?), so the agent didn’t fulfill any of his instructions.