John Gill Commentary 2 Timothy 3:9

"But they shall proceed no further. For their folly shall be evident unto all men, as theirs also came to be." — 2 Timothy 3:9 (ASV)

But they shall proceed no further
They may proceed to more ungodliness, and wax worse and worse in error; but they shall proceed no further than the magicians of Egypt, who did lying wonders, hardened Pharaoh's heart, and deceived him and the Egyptians; but could not destroy the Israelites, nor hinder their departure out of Egypt, when their time was come: so these wicked men do false miracles, harden the popes of Rome, and deceive the nations subject to them; but they cannot deceive the elect of God, nor destroy the church of God, against which the gates of hell cannot prevail; nor could they hinder the reformation, or the departure of the Lord's people out of Babylon.

For their folly should be manifest unto all [men], as theirs also
was ;
as the folly of Jannes and Jambres was, when Aaron's rod devoured theirs; and when they could not produce lice, but was obliged to own to Pharaoh, that that plague was the finger of God; and when they could not stand before Moses, because of the boils that were upon them, (Exodus 7:12) (Exodus 8:18Exodus 8:19) (9:11) . And so the Arabic version renders it, "as is manifest the folly, or madness of these two"; and it is notorious in how many instances the frauds, impostures, tricks, and villanies of the church of Rome, and its votaries, have been detected and exposed; which have been the means of hindering them from proceeding any further than they have. The Alexandrian copy reads, "their understanding"; that which they pretended to have of divine things.