TT #18 · Parashas Toldos · Passuk 26:5
inasmuch as Avraham obeyed Me and kept My charge: My commandments, My laws, and My teachings.”
Torah Temimah points to Yoma 28b. E-Daf · Sefaria — Yoma 28b
Rav said: Avraham our father fulfilled the entire Torah, as it is said “because Avraham obeyed My voice and kept My charge, My commandments, My statutes, and My teachings.”
Custom (Bavli — Avraham observed the entire Torah)
Avraham fulfilled the entire Torah; the layered language of the verse is the source for that claim.