Joseph ordered his magic astrolabe to be brought to him, whereby he knew all things that happen, and he said unto Benjamin, "I have heard that the Hebrews are acquainted with all wisdom, but dost thou know aught of this?" Benjamin answered, "Thy servant also is skilled in all wisdom, which my father hath taught me." He then looked upon the astrolabe, and to his great astonishment he discovered by the aid of it that he who was sitting upon the throne before him was his brother Joseph.
Noticing Benjamin's amazement, Joseph asked him, "What hast thou seen, and why art thou astonished?" Benjamin said, "I can see by this that Joseph my brother sitteth here before me upon the throne." And Joseph said: "I am Joseph thy brother! Reveal not the thing unto our brethren.
I will send thee with them when they go away, and I will command them to be brought back again into the city, and I will take thee away from them. If they risk their lives and fight for thee, then shall I know that they have repented of what they did unto me, and I will make myself known unto them. But if they forsake thee, I will keep thee, that thou shouldst remain with me. They shall go away, and I will not make myself known unto them."