(By Allah! Indeed you know that we came not to make mischief in the land, and we are no thieves!) `Ever since you knew us, you, due to our good conduct, became certain that,
In verse 74, it was said: قَالُوا فَمَا جَزَاؤُهُ إِن كُنتُمْ كَاذِبِي ، that is, the royal staff said to them: If it stood proved that they were liars, what do they suggest should be the punishment for the thef?
Tazkirul Quran
Maulana Wahiduddin KhanOn ayahs 68–74
The ancient capital of Egypt was a city around which there was a rampart with many gates in it. Jacob’s advice to his sons that they should not enter the city through the same gate, but through different gates was based on the fear that some enemy of theirs might try to kill them (Tafsir an-Nasafi). Verse 73 of this chapter clarifies the matter of this fear. In this Joseph’s brothers profess that they are innocent by saying that they had not come there to fight or steal. Joseph’s brothers had come to Egypt from foreign lands; their way of dressing was different from that of the local people; because of their appearance they would appear to be outsiders to the people of Egypt; the entry of eleven such persons together would have created suspicion in the eyes of the people. So in order to save them from any unnecessary clash with the local people, Jacob advised them not to band together in one group while entering the city. A believer’s eyes are ever on the supreme power of God; he observes that in this universe nobody has any power except God. At the same time he knows that this world is a testing ground. Owing to the exigencies of this test God has hidden all matters behind the veil of cause and effect. For this reason, Jacob advised his sons to take worldly precautions. But he also said that whatever happened, would happen at the instance of God, because nobody except God had any real power.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.