John Chrysostom

But it seems to me that by these words He intended covertly to proclaim that there were to be persecutions, as it would come to pass that many fathers would allure their sons to impiety, and many wives their husbands. Again He delays not to say, for my name's sake and the Gospel's, as Mark says, or for the kingdom of God, as Luke says; the name of Christ is the power of the Gospel, and of His kingdom; for the Gospel is received in the name of Jesus Christ, and the kingdom is made known, and comes by His name.

Catena Aurea by Aquinas ↗

Theophylact of Ohrid

Everyone who leaves wife or mother — He says this not so that we would leave our parents helpless or separate from our wives, but teaches us to prefer pleasing God above all things of the flesh. Since from the preaching of the Gospel war was to be kindled among people, so that children would have to renounce their fathers, the Lord says: whoever leaves for the sake of the Gospel fleshly kinship and in general all things of the flesh, that one will receive all this a hundredfold in this age, and in the age to come, eternal life.

Commentary on Mark ↗

Clement of Alexandria

"And Jesus answering said, Verily I say unto you, Whosoever shall leave what is his own, parents, and children, and wealth, for My sake and the Gospel's, shall receive an hundredfold." But let neither this trouble you, nor the still harder saying delivered in another place in the words, "Whoso hateth not father, and mother, and children, and his own life besides, cannot be My disciple." For the God of peace, who also exhorts to love enemies, does not introduce hatred and dissolution from those that are dearest. …

Who is the Rich Man that Shall Be Saved? ↗

Bede

Jesus responded and said: Amen I say to you: There is no one who has left house, or brothers, or sisters, or father, or mother, or children, or fields for my sake, and for the sake of the Gospel, who will not receive a hundred times as much now in this time, houses, and brothers, and sisters, and mothers, and children, and fields, with persecutions, and in the age to come, eternal life. …

On the Gospel of Mark ↗