Translation of the verse 66 from Surah Yusuf : Number of verses 111 - - page 243 - Part 13.
He [Ya'qub (Jacob)] 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, etc.)," And when they had sworn their solemn oath, he said: "Allah is the Witness over what we have said."
[Jacob] said, "Never will I send him with you until you give me a promise by Allah that you will bring him [back] to me, unless you should be surrounded by enemies." And when they had given their promise, he said, "Allah, over what we say, is Witness."
(12:66) Their father replied, "I will never send him with you until you give me a pledge in Allah's name that you shall bring him back to me unless it be that you are rendered helpless by circumstances." When they had given him their solemn pledges he said, "Note it well that Allah is guarding and watching over this pledge of ours. "