Ambrose of Milan — as excerpted in the Catena Aurea on Luke 20:9-18

“The vineyard is also our type. For the husbandman is the Almighty Father, the vine is Christ, but we are the branches. (John 15:5.) Rightly are the people of Christ called a vine, either because it carries on its front the sign of the cross, or because its fruits are gathered in the latter time of the year, or because to all men, as to the equal rows of vines, poor as well as rich, servants as well as masters, there is an equal allotment in the Church without distinction of persons. And as the vine is married to the trees, so is the body to the soul. Loving this vineyard, the husbandman is wont to dig it and prune it, lest it grow too luxuriant in the shade of its foliage, and check by unfruitful boastfulness of words the ripening of its natural character. Here must be the vintage of the whole world, for here is the vineyard of the whole world.”