Siman 563

(120.) I heard from Rabbainu o.b.m. that in the days of Abraham our father the Shechina was called by the name Sarah — and in the days of Isaac by the name Rebecca — and in the days of Jacob by the name Rachel and Leah. (Likutay Halachos, Laws of Meat and Milk, Law 2.) And so it is cited in the holy Zohar [Bereishis 112b] in this vein.