Sforno on Deuteronomy 33:4/ספורנו על דברים ל״ג:ד׳

1ישא מדברותיך, a reference to when the people said to G’d at the revelation at Mount Sinai that He should make Moses His intermediary, elevate him to communicate G’d’s words, conveying His words to them, as they were afraid they would i.e. if they had to listen to G’d’s voice directly any longer. (This is the meaning of Moses hearing the voice of the Lord speaking to him (only) in Numbers7,8 The word מדברותיך in this verse refers to the Torah, which was attributed to Moses, on account of the people preferring to hear its words from Moses’ mouth. This is why the Torah describes the people as saying תורה צוה לנו משה, “Moses has commanded the Torah to us,” instead of “G’d has commanded the Torah to us.” (verse 5)

2מורשה קהלת יעקב, when something has not been acquired directly but is inherited, i.e. handed over from another owner, it is described in terms of ירושה, an inheritance. Had the Jewish people not requested to hear the words of the Torah from Moses instead of from G’d Himself, Torah would not now be described as מורשה.