What did Kayin mean when he said "u'Mipnecha Esaser"? ...
Targum Onkelus and Targum Yonasan: "It is impossible to hide from You!"
Ramban: Kayin was pointing out that so embarrassed was he, that he was not able to stand before Hashem to Daven or to bring a Korban, only to hide from Him.
And when he said "Whoever finds me will kill me"?