Andrew of Caesarea
"And they sang the song of Moses." By the song of Moses, we suppose that a hymn is here offered up to God by those justified under the Law before grace.
By the song of the Lamb, we suppose that those who lived righteously on earth after the coming of Christ offer Him unceasing hymnody and thanksgiving.
They do so for the mercies and benefits sent by Him upon our race, for through the divine Apostles He called all nations to the knowledge of Himself.