COMMENTARY on 12:65
A. Yusuf Ali:

Translation:
Then when they opened their baggage, they found their stock-in-trade had been returned to them. They said: "O our father! What (more) can we desire? this our stock-in-trade has been returned 1726 to us: so we shall get (more) food for our family; We shall take care of our brother; and add (at the same time) a full camel´s load (of grain to our provisions). This is but a small quantity." 1727
Commentary:

1726  The ten brothers did not take their father's refusal as final. They opened their saddlebags, and found that the price they had paid for their provisions had been returned to them. They had got the grain free! What more could they desire? The spell which Joseph had woven now worked. If they only went back, this kind Wazir would give more grain if they pleased him. And the only way to please him was to take back their younger brother with them. It would cost them nothing. Judging by past experience they would get a whole camel's load of rain now. And so they stated their case to the aged father.

1727  Two meanings are possible—either or perhaps both. 'What we have brought now is nothing compared to what we shall get if we humour the whim of the Egyptian Wazir . And, moreover, Egypt seems to have plenty of grain stored up. What is a camel-load to her WazTr to give away?'

 

Muhammad Asad:

Translation:
Thereupon, when they opened their packs, they discovered that their merchandise had been returned to them; [and] they said: "O our father! What more could we desire? Here is our merchandise: it has been returned to us! [If thou send Benjamin with us,] we shall (again] be able to bring food for our family, and shall guard our brother [well], and receive in addition another camel-load of grain 64 That [which we have brought the first time] was but a scanty measure."
Commentary:
64  It would seem that Joseph used to allot to foreign buyers of grain one camel-load per person.