Qala maAAatha Allahi an na'khutha illa man wajadna mataAAana AAindahu inna ithan (surah Yusuf: 79)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(12:79) Joseph replied, "God forbid that we should seize any other than the one with whom we have found our property *63 : for, if we do this, we shall be unjust."

Qaala ma`aazal laahi an naakhuza illaa manw wajadnaa mataa`anaa `indahoo innaaa izal lazaalimoon

*63) The use of the words "with whom we have found our property" instead of the word "thief" is very significant. Prophet Joseph avoided the use of the word "thief" for his brother because he was not really a thief. This is called aiNaeE (touriyah), that is, to put a cover over a reality or "to hide a reality." Such a practice is allowed by the Muslim Law under certain conditions and with certain limitations. It may be practised not to gain any selfish end, but to ward off some evil or to protect and save an oppressed person from some oppressor, provided that no other course might have been left except saying something against the truth or of having a resort to a deceitful device. It is obvious that in such a case, a righteous person will not tell a blunt lie or resort to an open deceit. Instead, he will say something or do something that might not be strictly truthful or strictly right, yet at the same time is not a blunt lie, so that he might hide the reality to ward off the evil. Such a practice is lawful, legally and morally, provided that it is not practised to gain some personal or selfish ends but to ward off a greater evil with a lesser evil. Accordingly, Prophet Joseph scrupulously fulfilled all the conditions in this case. He placed the cup in the pack of his brother with his consent, but he did not ask his servants to make a search of his pack and accuse him of theft. After this, when the servants brought the brothers before him as suspects, he quietly rose from his seat and began to make a search of their packs. Then afterwards, when the brothers requested that one of them should be taken instead of Benjamin, he answered them back in their own words that he would detain only that person in whose possession the cup was found and none else.
Instances of such a practice during his campaigns are found in the life history of the Holy Prophet. And this cannot be regarded as morally objectionable according to any moral or legal standard.