"But his delight is in the law of the Lord." Rabbi Levi said, "There were six commandments that the Holy One, blessed be He, gave to Adam, as it is said, 'And the Lord God commanded the man.'" 'In His law doth he meditate day and night' refers to these six commandments that he was given.
"And it shall be like a tree planted, which the Lord took and planted in the Garden of Eden, whose fruit He shall give in its season – this refers to Cain. 'And its leaf shall not wither' – this refers to Abel. 'And all that he does shall prosper' – this refers to Seth. The wicked, however, are not so – this refers to the serpent. Therefore, the wicked shall not stand in the judgment, but everyone else will be healed in the World to Come, except for the serpent and the inhabitants of Giv'on, as it is said: 'The wolf and the lamb shall graze together' – this refers to the inhabitants of Giv'on, as it is written: 'And the idolatrous priests of the city shall come from all the tribes of Israel, to serve it' (Ezekiel 48:19). The Lord gave Israel three good traits: they are merciful, bashful, and benevolent, as it is written: 'And He will love you and bless you and multiply you; He will also bless the fruit of your womb and the fruit of your land, your grain and your new wine and your oil' (Deuteronomy 7:13). And it is also written: 'And in order that the fear of Him may be ever with you, so that you do not go astray' (Exodus 20:17). Hence, it is said that anyone who lacks shame is as if his ancestors were not present at Mount Sinai (Yoma 47a). And it is written: 'Therefore, keep the covenant and the mercy which the Lord swore to your fathers' (Deuteronomy 7:12). David saw that the inhabitants of Giv'on lacked all these traits, so he banished them, as it is written: 'But the Giv'onites were not of the children of Israel' (2 Samuel 21:2). Ezra also banished them, as it is written: 'And the Netinim dwelt in Ophel' (Nehemiah 11:21). Even the Lord distances Himself from them in the World to Come, as it is written: 'And the idolatrous priests of the city shall come from all the tribes of Israel, to serve it; and they shall not come near to Me, to serve as priests to Me' (Ezekiel 48:19). The servants mentioned in this verse are the inhabitants of Giv'on, who shall serve in the World to Come, as it is said: 'And Joshua made them hewers of wood and drawers of water' (Joshua 9:27). Thus, the way of the righteous is known – this refers to Adam and Eve, while the way of the wicked shall perish – this refers to the serpent, who shall not be healed in the World to Come." (Midrash Tehillim 1:7)