Adam Clarke on Luke 9:31

His decease - Την εξοδον αυτον, That going out (or death) of his. That peculiar kind of death - its nature, circumstances, and necessity being considered. Instead of εξοδον, thirteen MSS. have δοξαν, glory. They spoke of that glory of his, which he was about to fill up (πληρουν) at Jerusalem. The Ethiopic unites both readings. The death of Jesus was his glory, because, by it, he gained the victory over sin, death, and hell, and purchased salvation and eternal glory for a lost world.