Jamieson, Fausset and Brown on 2 Timothy 2:20

20. in a great house--that is, the visible professing Christian Church (1Ti 3:15). Paul is speaking, not of those without, but of the [visible] family of God [Calvin]. So the parable of the sweep-net (Mt 13:47-49) gathering together of every kind, good and bad: as the good and bad cannot be distinguished while under the waves, but only when brought to shore, so believers and unbelievers continue in the same Church, until the judgment makes the everlasting distinction. "The ark of Noah is a type of the Church; as in the former there were together the leopard and the kid, the wolf and the lamb; so in the latter, the righteous and sinners, vessels of gold and silver, with vessels of wood and earth" [Jerome, Dialogue against the Luciferians, 302] (compare Mt 20:16).

vessels of gold ... silver--precious and able to endure fire.

of wood and earth--worthless, fragile, and soon burnt (1Co 3:12-15; 15:47).

some ... some--the former ... the latter.

to dishonour--(Pr 16:4; Ro 9:17-23).