COMMENTARY on 12:63
A. Yusuf Ali:

Translation:
Now when they returned to their father, they said: "O our father! No more measure of grain shall we get (unless we take our brother): So send our brother with us, that we may get our measure; and we will indeed take every care of him." 1724
Commentary:

1724  On their return they no doubt told Jacob all that had transpired. But to beg Benjamin of him was no easy matter, as Jacob did not trust them and had no cause to trust them after their treatment of Joseph. So they use the argument of urgent necessity for all it is worth.

 

Muhammad Asad:

Translation:
And so, when they returned to their father, [Joseph's brothers] said: "O our father! All grain 62 is [to be] withheld from us [in the future unless we bring Benjamin with us]: send, therefore, our brother with us, so that we may obtain our measure (of grain]; and, verily, we shall guard him well!"
Commentary:
62  Lit., "measure [of grain]", here used metonymically in an allusion to Joseph's words (verse 60).