The Genesis narrative tells us that the Lord had no respect for Cain's offering, as he had that of Abel, his brother's. The reason for this must have been a wrong spirit in Cain (Gen. 4:3-7). Verse 7 states: "If thou doest well, shalt thou not be accepted? And if thou doest not well sin lieth at the door." There have been many interpretations suggested for the last part of this verse; but whatever translation may be given the specific words, the whole narrative implies that the trouble with Cain was with his motive. He did not come humbly, worshipfully, as Abel did, and probably his offering was less costly, less of a real sacrifice. Again, it has been thought that in the acceptance of the animal sacrifice and the rejection of the fruit sacrifice there was a suggestion of the fact that sin requires death for an atonement. Abel's was the first of the long line of offerings for sin in which blood was shed, culminating in the sacrifice of Christ's body on the cross. The mark upon Cain has been a fertile subject of conjecture among Biblical scholars. Some hold that it was probably a sign given to Cain as assurance that no man should kill him, but the nature of the sign, and whether it was something perceptible to others, are left in uncertainty. One commentator suggests that it may have been an aspect of such ferocity that he became an object of horror and avoidance. Lastly, the question is asked about the land of Nod, to which Cain was banished after the murder of Abel and where he found his wife. The land of Nod means simply "land of exile." We may gather from Gen. 4:14-15 that at the time referred to, the human family had multiplied considerably. Cain's wife was doubtless some blood relative, probably a sister. An ancient Arab tradition states that her name was Azura. From the account in Genesis, we may conjecture that al though only four persons are mentioned in the sacred narrative up to this point, the human race had increased rapidly (Josephus says that the Jews held a tradition that Adam had thirty-three sons and twenty-three daughters). Cain's fear of punishment may therefore have been directed toward his own relatives.