'ויאמר ה, the reason God spoke to him now was only in order to show him that he could not hide his deed from God, and that whatever man does, or even plans to do is fully known to Him. Kayin had thought that by burying Hevel he could hide his deed from God, just as he had been able to hide it from his father. This is why he had killed Hevel in the field where there had not been any witnesses. The additional reason why God addressed him was to inform him of his impending punishment. The reason that God phrased His remarks as if He questioned him, saying: אי הבל אחיך, was only an opening line, just as He had asked Adam in 3,9 איכה, “where are you?,” knowing full well where Adam was hiding. He also had asked Moses in Exodus 4,2 מזה בידך, “what is this in your hand?,” knowing full well that Moses held a staff in his hand. There are more such examples of a question by God being for purposes other than to obtain information not at His disposal. Seeing, however, that He had not said to Kayin: “why did you kill your brother?” Kayin thought that God was not yet aware of Hevel being dead. He denied all knowledge, saying: לא ידעתי, השומר אחי אנכי, claiming that Hevel had gone about his work just as he, Kayin, had gone about his work.. He added, gratuitously, that he could not be expected to know the whereabouts of his brother all the time, seeing he had not been hired to be his keeper. He acted far worse than his father at the time, as Adam had never denied that he had done wrong. He had only made excuses for himself. Adam was well aware that God was well informed about all such matters, and that even though He had commenced the conversation with a question, it was not because He had not known the answer.