28 But the majesty of the angel was manifested in itself; the weakness of flesh in itself could not endure. For my inward parts were turned into corruption. But yet men see men, their fellows, and faint before them: Yet it is not by their bright splendour that they are moved, but by their harsh will. For servants are terrified by the wrath of their masters, and those that are judged tremble through fear of their judges. But this did not befall Daniel on account of threatening or anger from the angel; but on account of his terrible nature and prevailing brightness.
For it was not with threatening, the angel came to him. For if he had come with threatening, how could a mouth full of threatening become full of peace, when it came, saying, Peace be unto you, you man of desire? Thus that mouth that was a fountain of thunderings— for the voice of his words was like the voice of many hosts, that voice became to him a fountain teeming with and containing peace. And when [the voice] reached the terrified ears which were thirsty for the encouraging greeting of peace, there was opened and poured out [for Daniel] a draught of peace.
And by the angel's later [word of] peace, those ears were encouraged, which had been terrified by his former voice first. For [he said], Let my Lord speak because I have been strengthened. But because in that heart-moving vision the fiery angel was about to announce nothing concerning Him, [the Lord], on this account that majesty [of the angel] was forward to give the salutation of peace to the lowliness [of the prophet]; that by the gladdening salutation which that awful majesty gave, the dread should be removed which lay on the mind of the lowliness and that was terrified.
Source: On Our Lord (New Advent)