Translation:

90. They said: "Art thou indeed Joseph?" He said: "I am Joseph and this is my brother: Allah has indeed been gracious to us (all): behold he that is righteous and patient never will Allah suffer the reward to be lost of those who do right."

Notes (Tafseer)

1766. Their father's words, the way events were shaping themselves. Joseph's questionings, perhaps Benjamin's manner now, not a slave kept in subjection but one in perfect love and understanding with this great Wazir,-perhaps also a recollection of Joseph's boyish dream,-all these things had prepared their minds and they ask the direct question, "Art thou Joseph?" They get the direct reply, "Yes, I am Joseph; and if you have still any doubt of my identity, here is Benjamin: ask him. We have suffered much, but patience and right conduct are at last rewarded by Allah!"