Rashi defines naval as vile as a result of our lack of gratitude to Hashem Who has done everything for us. An ingrate is both an abominable person and unwise, because, when people see his lack of human decency, they will distance themselves from him. Targum Onkeles offers a novel exposition in which he translates am naval as ama d’kablu Oraysa, the nation that received the Torah. This translation begs elucidation. Why should the nation that accepted the Torah be described as naval (which is normally defined as abomination or another uncomplimentary term)? Horav Eliyahu Schlessinger, Shlita, offers an innovative rendering of naval, which he applies to Targum Onkeles’ exposition.
The Midrash Rabbah (Bereishis 17:5) states: Shloshah novlos hein; there are three offshoots: the offshoot of death is sleep; the offshoot of prophesy is a dream; the offshoot of Olam Habba, the World to Come, is Shabbos. Rabbi Avin adds, “The offshoot of Heavenly light is the sun. The offshoot of Heavenly wisdom is the Torah.” In summary, Chazal define novlos/navel as dugmah, example, offshoot, crumb, feint likeness. Sleep is a miniscule example, a mere crumb of death. Likewise, dreaming, Shabbos, and Torah are smidgeons of something much, much greater. One who seeks a bare semblance of the essence of Heavenly wisdom, let him study Torah. Through ameilus, toil, in studying Torah, he will derive somewhat the meaning and depth of Heavenly wisdom.
Thus, we may posit that naval here is derived/related to novlos. The pasuk teaches us that when one considers himself to be a baal davar, someone of substance, one to reckon with, distinguished, as the result of the wisdom he derived from studying Torah, this is because he is a member of am naval, the nation that received the Torah, which is only a glimmer of the real thing. What does man – even if he is knowledgeable in Torah – have to arrogate about? What right does he have to repay bad for good to his Creator? Whatever wisdom he possesses has been imparted to him from the Torah, which is authored by Hashem, and represents an inkling of Divine Wisdom. So, it is best that he be grateful for what he has and manifest the proper acknowledgement to the true Source of his wisdom.