The slander of which Jacob spoke referred to what Potiphar had said of Joseph before Pharaoh. He had complained, saying, "Why didst thou appoint my slave, whom I did buy for twenty pieces of silver, to be ruler over the Egyptians?" Joseph had then taken up his own defense, saying: "When thou didst buy me as a slave, thou didst commit a capital crime. Only a descendant of Canaan may be sold as a slave, and I am a descendant of Shem, and a prince besides. If thou wilt convince thyself of the truth of my words, do but compare me with the likeness of my mother Sarah that Pharaoh had made of her!" They brought Sarah's likeness, and, verily, it appeared that Joseph resembled his ancestress, and all were convinced of his noble lineage.