“And you shall love your neighbor as yourself”
(Leviticus 19:18).
Rabbi Aqiva says:
"This is the main principle of the Torah".
However, Ben Azzai says:
“This is the book of the generations of Adam”
(Gen 5:1)
– This is the main principle of the Torah !
[ספרא, קדושים, ד' פ"ט ע"ב]
