Before revision: 19:18 is a discussion recordedSifra, Kedoshim, 4; compare Genesis Rabbah 24:5 between Rabbi Akiva, who declared this verse in Leviticus to contain the great principle of the Law ("Kelal gadol ba-Torah"), and Ben Azzai, who pointed to Genesis 5:1 ("This is the book of the generations of Adam; in the day that God created man, in the likeness of God made he him"), as the verse expressing the leading principle of the Law, obviously because the first verse gives to the term "neighbor" its unmistakable meaning as including all men as being sons of Adam, made in the image of God.
After revision: 19:18 is a discussion recordedSifra, Kedoshim, 4; compare Genesis Rabbah 24:5 between Rabbi Akiva, who declared this verse in Leviticus to contain the great principle of the Law ("Kelal gadol ba-Torah"), and Ben Azzai, who pointed to Genesis 5:1 ("This is the book of the generations of Adam; in the day that God created man, in the likeness of God made he him"), as the verse expressing the leading principle of the Law, apparently because verse 5:1 gives the term "neighbor" its meaning as including all men as being sons of Adam, made in the image of God.