If the countenance of Moses does not resemble the countenance of Abraham one cannot acquire the Torah… Whoever studies Torah but does not have the countenance of our father Abraham – features of charity, features of the attribute of compassion –"the law of kindness on his tongue"– cannot acquire the Torah. The angels, the absolute truth of holiness, are unwilling to give him the Torah, because Torah without derech eretz [common decency] is dangerous. Moses without Abraham is, as it were, impossible.
If the Law of Moses is severed from Abraham's attributes, then the angels refuse to give the Torah. This is an extremely important issue, because many of Moses' students who study Torah as Halacha have regretfully forgotten that Moses was a son of Abraham. They have forgotten the connection between our father Abraham's attributes and the Law of Moses.