A Blessing in the Holy of Holies

Rebbi Yishmael himself told of an experience he had as Kohen Gadol. “Once I entered the inner sanctuary of the Beis HaMikdash to offer the incense,” he said, “and I saw Hashem sitting on a high and exalted throne. He said to me, ‘Yishmael, my son, bless Me.’ I said to Him, ‘May it be Your will that Your compassion be revealed over Your other attributes, and that You conduct Yourself toward Your children with compassion and beyond the letter of the law.’ And He nodded His head.”

Rashi explains that the nod was Hashem's way of agreeing to the blessing, as if answering Amen.