מדרש אויף ישעיהו 31:5

"and I shall see the blood": R. Yishmael was wont to say: Isn't everything revealed to Him, viz. (Daniel 2:22) "He knows what is in the darkness, and light dwells with Him," and (Psalms 139:12) "Darkness, too, is not dark for You." What, then, is the intent of "And I shall see the blood"? In reward for the mitzvah that you do, I shall reveal Myself with compassion to you, as it is written (Ibid.) "ufasachti upon you," "pesichah" connoting life, as in (Isaiah 31:5) "As birds that fly, so will the L–rd of hosts shield Jerusalem, shielding and saving, paseach and rescuing."