Bede the Venerable — as excerpted in the Catena Aurea on Luke 24:50-53

“And observe that among the four beasts in heaven, (Ezek. 1:10. Rev. 4:7) Luke is said to be represented by the calf, for by the sacrifice of a calf, they were ordered to be initiated who were chosen to the priesthood; (Exod. 29:1.) and Luke has undertaken to explain more fully than the rest the priesthood of Christ; and his Gospel, which he commenced with the ministry of the temple in the priesthood of Zacharias, he has finished with the devotion in the temple. And he has placed the Apostles there, about to be the ministers of a new priesthood, not in the blood of sacrifices, but in the praises of God and in blessing, that in the place of prayer and amidst the praises of their devotion, they might wait with prepared hearts for the promise of the Spirit.”