“Residing in Eretz Yisrael is equivalent to the rest of the mitzvot combined”
Sifre on Dvarim 12 and Tosefta Av.Z. 5,2 and cited by the Pitchei Tshuva Ev.H. 75,6.
“the peg upon which the entire Torah hangs”
R. Ya’akov Emdin, Siddur Beit Ya’akov p.13.
a mitzva which “encompasses the entire Torah”.
Or HaChayim, Dvarim 30,20.
Rav Ari Shvat (Chwat), Rosh Midreshet Tal Orot, Michlelet Orot, Elkana, in blog Tomar Devorah
There are other similar statements from Chazal concering tzitzis, niddah, and I believe, Shabbos. R' Wolbe has a whole book about this.
We tend to only hear about Talmud Torah being c'neged culam.
