Avraham merits disclosure through constant deveikus

בפסוק וה' אמר המכסה אני כו' אשר אני עושה.

On the verse, "And Hashem said: Shall I conceal from Avraham what I am doing?" (Bereishis 18:17)

He opens on the verse where Hashem decides not to hide the impending judgment of Sodom from Avraham.

בכמה מקומות דכתיב וה' דרשו חז"ל הוא וב"ד.

In several places where it is written "va'Hashem" (and Hashem), Chazal expounded that it means "He and His court (beis din)."

Chazal teach that the phrasing "and Hashem" (with the connecting "vav") indicates Hashem together with His heavenly court — the attribute of strict judgment, middas hadin.

יתכן לומר שזכה במדה"ד אאע"ה שלא להעלים ממנו דבר לאשר האבות הן המרכבה ולא עשו שום דבר רק בדביקות עליון ולא נשכח יראת ה' מהם אפילו שעה א' לכן שילם לו כמדתו שלא לכסות ממנו שום דבר.

It may be said that Avraham Avinu, peace be upon him, merited even according to the attribute of judgment (middas hadin) that nothing be hidden from him — because the Avos are the Merkavah (the Chariot), and they did nothing except in supernal deveikus, and the yiras Hashem never departed from them even for a single hour; therefore He repaid him measure for measure (k'middaso), not to conceal anything from him.

Even strict judgment ruled in Avraham's favor: since the Avos were the very "chariot" upon which the Shechinah rests — acting only in constant cleaving to Hashem, never losing their yiras Shomayim for a moment — Hashem rewarded Avraham midah k'neged midah, hiding nothing from him.

וזה עצמו המשך הפסוק ואברהם הי' יהיה כו' לאשר כל מה שעושין בהשתתפות שם שמים קיים לעד:

And this itself is the continuation of the verse, "and Avraham shall surely become [a great and mighty nation], etc." — because everything that is done in partnership with the Name of Heaven endures forever.

The verse continues that Avraham will surely become a great nation — for whatever a person does in partnership with Hashem, with constant deveikus, has eternal endurance, which is why nothing of Avraham's would be concealed or lost.

Summary: Hashem revealed His plan for Sodom to Avraham even under middas hadin, because the Avos were the Merkavah — acting solely in supernal deveikus and never losing yiras Hashem for even an hour. Avraham was thus repaid measure for measure with full disclosure, illustrating that whatever is done in partnership with Hashem endures forever.