Siman 516

(73.) He said that in the Future the tzaddikim will say: "This is G-d, we have hoped for Him" [Taanis 31a] — specifically "this one." And he said in Yiddish that they will say: "Truly to this G-d we had hoped" ["takeh tsu dem Got hobn mir gehat"]. Meaning — that also in this world they had merited to attain Him thus, as they are now seeing Him. And they had always been hoping to see Him thus. And now they have merited to this. And therefore they will then say: "This is G-d, we have hoped for Him" — specifically "this."