Bede the Venerable: Jerome on the Fire of Present Temptations

Each one, in fact, is tempted, drawn on and lured by his own concupiscence, and so on, drawn on from the right way and lured into evil. About this verse Jerome writes against Jovinian (Against Jovinian 2.3):

Just as in good works, (he says) the perfecter is God, for it depends not on the will or striving but on God's having mercy (Romans 9:16), and helping us to be able to reach the goal, so in evils and sins the seeds are our own prompting, perfection the devil's. When he sees that on the foundation of Christ we have built hay, wood, straw, he adds fire; let us build gold, silver, precious stones, (1 Corinthians 3:12) and he will not dare to tempt. Although even in this let there not be definite and secure possession. In truth a lion sits in ambush in hiding that he may kill the innocent. (Psalm 10:8 (9:29)) And, The furnace tests the vessels of the potter, the temptation of tribulations, however, the righteous men. (Sirach 27:6)

Bede the Venerable, Commentary on the Seven Catholic Epistles, at James 1:14 (Cisterian Studies Series, #82, p. 14), translated by Dom David Hurst, O.S.B.