Charles Ellicott Commentary Genesis 42:22

"And Reuben answered them, saying, Spake I not unto you, saying, Do not sin against the child; and ye would not hear? therefore also, behold, his blood is required." — Genesis 42:22 (ASV)

His blood. — Evidently they thought that Joseph was dead, so that the accusation brought against them of falsehood for saying in Genesis 42:13 one is not is groundless. Moreover, Jacob uses the same words of Simeon (Genesis 42:36), meaning by it only that he was lost to him.