Rashi: The Torah is issuing a stern warning to take steps not to forget one's learning. ¹

Seforno: It implies that one should learn Torah in order to comprehend His Chasadim via which one comes to love Him.

Rashi (citing Shabbos, 133b): 'Mah Hu Rachum, af Atah Rachum - Mah Hu Gomel Chasadim, Af Atah Tigmol Chasadim!' (Just as Hashem is merciful, so too, should you should be merciful; just as He bestows Chesed, so too should you

Rashi: The Torah means that one should cleave to Talmidei-Chachamim and it will be considered as if one is cleaving to Hashem. ¹

Ramban #1 (citing the Ibn Ezra): It means to love Hashem and to go in His ways in order to cleave to Him in the end. ²

Ramban #2: With reference to Avodah-Zarah, it entails constantly cleaving to Hashem in one's mind to the exclusion of all other deities.

Ramban #3: The Torah means that one's mind should constantly cleave to Hashem - to think about Him and about loving Him when one goes on one's way, when one lies down and when one gets up - to the point that even when one speaks to other people, one haas Him in mind. ³

Seforno: It means that everything that one does (even one's mundane activities) should be in order to serve Hashem. ⁴

Targum Onkelos and Targum Yonasan: What the Torah means is that one should come close to His service.

Mesilas Yesharim #1 (Perek 1): Everything that can bring him close to Hashem, he pursues it, and whatever can block being close to Hashem, he flees from it, like from a fire.

Mesilas Yesharim #2 (Perek 19): 'Deveikus' means that a person cannot separate or budge from Him.

Kesuvos, 111b: Anyone who marries off his daughter to a Talmid-Chacham, who does business with a Talmid-Chacham or ho benefits a Talmid-Chacham from his property is considered as if he cleaved to the Shechinah. ⁵