Theophylact of Ohrid

For we must not allow any time to lapse, but at once follow the Lord.

Catena Aurea by Aquinas ↗

Augustine of Hippo

They did not follow Him in such manner as that they should cleave to Him; for it is plain when they cleave unto Him, for He called them from the ship. For one of the two was Andrew, as you have just heard, and Andrew was the brother of Peter; and we know from the Gospel that the Lord called Peter and Andrew from the ship, saying, "Come ye after me, and I will make you fishers of men." And from that time they clave unto Him, so as not to go away. …

Tractates on John 7 ↗

Gregory the Dialogist

You have heard, dearest brothers, that at the voice of a single command, Peter and Andrew, leaving their nets, followed the Redeemer. They had seen him perform no miracles yet, they had heard nothing from him about the reward of eternal recompense; and yet at one command of the Lord they forgot what they seemed to possess. How many of his miracles do we see, with how many scourges are we afflicted, by how many harsh threats are we deterred, and yet we disdain to follow him when he calls? …

Forty Gospel Homilies, Homily 5 ↗