Moshe saw his prophecy באספקלריה מאירה [a clear looking glass] and due to his clear vision did not merit to "see" Hashem b/c "כי לא יראני האדם וחי" - You can't clearly see Hashem and live. Yeshayahu saw באספקלריה שאינה מאירה [an unclear looking glass] and thus merited to "see" Hashem. "ואראה את אדני ישב על כסא רם ונשא" [See Yevamos 49b]. Since his vision was blurred, he was able to get a glimpse of the Divine. Sort of like [להבדיל] being able to look at the sun if you are wearing sunglasses.
There is a Machlokes whether Prophecy is on the same level as seeing angels [Rambam] or whether Prophecy is a higher level than seeing angels [see Ramban 18-1]. Avraham first prophesied and then saw angels. First "וירא אליו השם" and then "וישא עיניו וירא והנה שלשה אנשים". However we can't compare this revelation to that of Moshe was was the greatest Navi ever. "ולא קם בישראל כמשה". Yet, the Medrash says that when Moshe Rabbeinu went to Shomayim, the angels wanted to harm him so Hashem made Moshe look like Avraham and told the angels "Are you not embarrassed from him? You went down and ate in his house". In other words, Moshe was masked with Avraham's face, meaning, that his level of Prophecy אספקלריה מאירה needed Avraham's level of Prophecy. It emerges that Avraham's level of Prophecy, behind which shines the image of Moshe, is higher than אספקלריא שאינה מאירה and below Moshe's level of אספקלריא מאירה but in between.
Avraham merits ראייה - seeing, which is then contracted to speech and that is the mask of Avraham's face that Moshe merited when he went to Shomayim and had to prove to the angels that only we are connected to the world of action [see Shabbos 89a]. Moshe himself first merited many revelations of Hashem speaking to him and then asked to see Him "הראני נא".
The seeing of Avraham was contracted to speech that told him that Hashem was gong to destroy Sodom. The Medrash says that Hashem felt that he had to tell Avraham about His plans b/c he promised the Land to Avraham and now he was going to overturn Sodom. The reason Sodom was destroyed was b/c of the cry of the young girl: There was a young woman who would take bread out to the poor people in a pitcher so the people of Sodom would not see it. The matter was revealed, and they smeared her with honey and positioned her on the wall of the city, and the hornets came and consumed her. And that is the meaning of that which is written: “And the Lord said: Because the cry of Sodom and Gomorrah is great [rabba]” (Genesis 18:20). And Rav Yehuda says that Rav says: Rabba is an allusion to the matter of the young woman [riva] who was killed for her act of kindness. It is due to that sin that the fate of the people of Sodom was sealed.
To be continued, I hope....
