Gregory the Great — as excerpted in the Catena Aurea on Luke 14:25-27

“(in Hom. 37. in Ev.) Or because the cross is so called from torturing. In two ways we bear our Lord’s cross, either when by abstinence we afflict our bodies, or when through compassion of our neighbour we think all his necessities our own. But because some exercise abstinence of the flesh not for God’s sake but for vain-glory, and shew compassion, not spiritually but carnally, it is rightly added, And, cometh after me. For to bear His cross and come after the Lord, is to use abstinence of the flesh, or compassion to our neighbour, from the desire of an eternal gain.”