28 Then, after standing for some time, I said to the Emperor: “Let me offer for you without anxiety, set my mind at ease.” As he continued sitting and nodded, but did not give an open promise, and I remained standing, he said that he would amend the edict. I went on at once to say that he must end the whole investigation, lest the Count should use the opportunity of the investigation to do any injury to the Christians. He promised that it should be so. I said to him, “I act on your promise,” and repeated, “I act on your promise.” “Act,” he said, “on my promise.” And so I went to the altar, whither I should not have gone unless he had given me a distinct promise. And indeed so great was the grace attending the offering, that I felt myself that that favour granted by the Emperor was very acceptable to our God, and that the divine presence was not wanting. And so everything was done as I wished.
Source: Letters (New Advent)