John Chrysostom

For refusing to believe the words of warning they were suddenly visited with a real punishment from God; but their unbelief proceeded from self-indulgence, and softness of mind. For such as a man's wishes and inclinations are, will also be his expectations. Therefore it follows, they eat and drank.

Catena Aurea by Aquinas ↗

Bede

Now Noah builds the ark mystically. The Lord builds His Church of Christ's faithful servants, by uniting them together in one, as smooth pieces of wood; and when it is perfectly finished, He enters it: as at the day of Judgment, He who ever dwells within His Church enlightens it with His visible presence. But while the ark is in building, the wicked flourish, when it is entered, they perish; as they who revile the saints in their warfare here, shall when they are crowned hereafter be smitten with eternal condemnation.

Catena Aurea by Aquinas ↗

Bonaventure

Second, as to the cause of the flood, he adds: They were eating and drinking, marrying wives and being given in marriage, until the day when Noah entered the ark, that is, they were entirely devoted to the works of the flesh, and therefore were worthy to be corrupted and destroyed in their corruptible flesh. Hence the Gloss of Ambrose: "Neither marriages nor food are condemned, since in the former the supports of succession, and in the latter those of nature, are established; but the immoderate use of lawful things is reproved. …

Commentary on Luke, Chapter 17 ↗