And when they opened their baggage, they found their merchandise returned to them. They said, "O our father, what [more] could we desire? This is our merchandise returned to us. And we will obtain supplies [i.e., food] for our family and protect our brother and obtain an increase of a camel's load; that is an easy measurement."
Allah says, when Yusuf's brothers opened their bags, they found their merchandise inside them, for Yusuf had ordered his servants to return it to their bags. When they found their merchandise in their bags,
قَالُواْ يأَبَانَا مَا نَبْغِى
(They said: "O our father! What (more) can we desire..."), what more can we ask for,
هَـذِهِ بِضَـعَتُنَا رُدَّتْ إِلَيْنَا
(This, our money has been returned to us;) Qatadah commented (that they said), "What more can we ask for, our merchandise was returned to us and the `Aziz has given us the sufficient load we wanted" They said next,
وَنَمِيرُ أَهْلَنَا
(so we shall get (more) food for our family,), `if you send our brother with us the next time we go to buy food for our family,'
وَنَحْفَظُ أَخَانَا وَنَزْدَادُ كَيْلَ بَعِيرٍ
(and we shall guard our brother and add one more measure of a camel's load.) since Yusuf, peace be upon him, gave each man a camel's load of corn.
ذلِكَ كَيْلٌ يَسِيرٌ
(This quantity is easy (for the king to give).) They said these words to make their case more appealing, saying that taking their brother with them is worth this gain,
(He Ya`qub (Jacob) said: "I will not send him with you until you swear a solemn oath to me in Allah's Name..."), until you swear by Allah with the strongest oath,
لَتَأْتُنَّنِى بِهِ إِلاَّ أَن يُحَاطَ بِكُمْ
(that you will bring him back to me unless you are yourselves surrounded (by enemies)), unless you were all overwhelmed and were unable to rescue him,
فَلَمَّآ ءَاتَوْهُ مَوْثِقَهُمْ
(And when they had sworn their solemn oath), he affirmed it further, saying,
اللَّهُ عَلَى مَا نَقُولُ وَكِيلٌ
(Allah is the Witness to what we have said.) Ibn Ishaq commented, "Ya`qub did that because he had no choice but to send them to bring necessary food supplies for their survival. So he sent Binyamin with them."
And when they opened their baggage, they found their capital given back to them. They said, "Our father, what else do we want? Here is our capital given back to us, and we shall bring food to our family, protect our brother and add the measure of one camel more. That is an easy measure."
It will be noticed that, prior to this verse, the brothers of Sayyidna Yusuf (علیہ السلام) were talking about what had happened to them on their journey, before they had opened their baggage. After that, when they opened the baggage and saw that their entire capital with which they had paid for the food grains was present inside the baggage, they realized that this was not done by mistake, in fact, their capital had been returned to them. Therefore, they said: رُدَّتْ إِلَيْنَا (given back to us). Then, to their father they said: مَا نَبْغِي (what else do we want?) that is, ` the grains are here and what we paid for it has also been returned to us. Now we should definitely go back there in peace with our brother because the way we have been treated shows that the ` Aziz of Misr is kind to us. We should have no apprehensions. It is the time that we go and bring food-grains for the family and take care of our brother too. That we shall get an additional load of grains in the name of our brother will help - because, whatever we have brought in the present trip is much less than our needs and is likely to be consumed soon.
One sense of the sentence: مَا نَبْغِي (ma nabghi) spoken by the brothers of Sayyidna Yusuf (علیہ السلام) is practically the same as given immediately above, that is, ` what else do we want?' And if, in this sentence, the letter: مَا (ma : not) is taken in the sense of negation, it could also mean that the sons of Sayyidna Ya` qub (علیہ السلام) told their father: Now that we have the price of the grain with us, we do not want anything from you. You just send our brother with us.
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 64–65
Joseph probably felt that it was discourteous to take the price of the corn from his brothers, or he perhaps thought that a lack of money might prevent them from coming back again. Therefore, he instructed his men that whatever amount his brothers had paid towards the corn should be quietly put among their belongings, so that when they went home and opened their bundles, they would find it and come again with their brother, Benjamin. Jacob, on the one hand, expressed his lack of trust in his sons where Benjamin was concerned. On the other hand, he also said that neither they nor anybody else had any power. Whatever God wished was bound to happen. But this happening is caused by human hands, so that an evil person, by performing evil deeds, may lay bare the truth about himself, while the good person, by performing righteous deeds, may have his name listed among the righteous.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.