Allah says that when they went back to their father,

[قَالُواْ يأَبَانَا مُنِعَ مِنَّا الْكَيْلُ]

(they said: "O our father! No more measure of grain shall we get...'') `after this time, unless you send our brother Binyamin with us. So send him with us, and we shall get our measure and we shall certainly guard him.' Some scholars read this Ayah in a way that means, `and he shall get his ration.' They said,

[وَإِنَّا لَهُ لَحَـفِظُونَ]

(and truly, we will guard him.), `do not fear for his safety, for he will be returned back to you.' This is what they said to Ya`qub about their brother Yusuf,

[أَرْسِلْهُ مَعَنَا غَداً يَرْتَعْ وَيَلْعَبْ وَإِنَّا لَهُ لَحَـفِظُونَ ]

("Send him with us tomorrow to enjoy himself and play, and verily, we will take care of him.'') [12:12] This is why Prophet Ya`qub said to them,

[هَلْ آمَنُكُمْ عَلَيْهِ إِلاَّ كَمَآ أَمِنتُكُمْ عَلَى أَخِيهِ مِن قَبْلُ]

(Can I entrust him to you except as I entrusted his brother [Yusuf] to you aforetime) He asked them, `Will you do to him except what you did to his brother Yusuf before, when you took him away from me and separated me from him'

[فَاللَّهُ خَيْرٌ حَـفِظًا]

[وَهُوَ أَرْحَمُ الرَحِمِينَ]

(But Allah is the Best to guard, and He is the Most Merciful of those who show mercy.) Ya`qub said, `Allah has the most mercy with me among all those who show mercy, He is compassionate with me for my old age, feebleness and eagerness for my son. I invoke Allah to return him to me, and to allow him and I to be together; for surely, He is the Most Merciful of those who show mercy.'

[وَلَمَّا فَتَحُواْ مَتَـعَهُمْ وَجَدُواْ بِضَـعَتَهُمْ رُدَّتْ إِلَيْهِمْ قَالُواْ يأَبَانَا مَا نَبْغِى هَـذِهِ بِضَـعَتُنَا رُدَّتْ إِلَيْنَا وَنَمِيرُ أَهْلَنَا وَنَحْفَظُ أَخَانَا وَنَزْدَادُ كَيْلَ بَعِيرٍ ذلِكَ كَيْلٌ يَسِيرٌ - قَالَ لَنْ أُرْسِلَهُ مَعَكُمْ حَتَّى تُؤْتُونِ مَوْثِقًا مِّنَ اللَّهِ لَتَأْتُنَّنِى بِهِ إِلاَّ أَن يُحَاطَ بِكُمْ فَلَمَّآ ءَاتَوْهُ مَوْثِقَهُمْ قَالَ اللَّهُ عَلَى مَا نَقُولُ وَكِيلٌ ]

(65. And when they opened their bags, they found their money had been returned to them. They said: "O our father! What (more) can we desire This, our money has been returned to us; so we shall get (more) food for our family, and we shall guard our brother and add one more measure of a camel's load. This quantity is easy (for the king to give).'') (66. He [Ya`qub] said: "I will not send him with you until you swear a solemn oath to me in Allah's Name, that you will bring him back to me unless you are yourselves surrounded (by enemies),'' And when they had sworn their solemn oath, he said: "Allah is the Witness to what we have said.'')