The Gemara at Sanhedrin 94a suggests that G-d wanted Hezekiah to be the Messiah. The Gemara continues to say that at some point Hashem said he would not be the Messiah, and Isaiah cried out "Woe to me! When will the Messiah come?" Was Isaiah privy to G-d's desire that Hezekiah could be the Messiah? At what point does the realization that he would not be the messiah -- as described in the Gemara -- actually come to Isaiah (who was Hezekiah's father-in-law as well as mentor)? I don't see it in the text.