Theophylact of Ohrid — as excerpted in the Catena Aurea on Luke 12:35-40

“Or, He will gird Himself, in that He imparts not the whole fulness of blessings, but confines it within a certain measure. For who can comprehend God how great He is? Therefore are the Seraphims said to veil their countenance, because of the excellence of the Divine brightness. It follows, and will make them to sit down; for as a man sitting down causes his whole body to rest, so in the future coming the Saints will have complete rest; for here they have not rest for the body, but there together with their souls their spiritual bodies partaking of immortality will rejoice in perfect rest.”