Theophylact of Ohrid

Since it has been proven concerning the Divine nature that God is neither Himself tempted nor tempts others, here by "temptations" he means thoughts that disturb the soul, for temptations from God do not disturb but strengthen the soul by illuminating it, which is why he says: "every good gift and every perfect gift is from above, coming down from the Father of lights" (Jas. 1:17), whereas everything that proceeds from us has imperfection.

Commentary on James ↗

Augustine of Hippo

Each one of us is tempted by our own lust, so let us fight and resist and not give in nor allow ourselves to be lured by it, nor allow it to conceive anything to which it might then give birth. It is like this—lust coaxes and coddles you, it excites and urges you on, positively encouraging you to do something wrong. Do not give in and it will not conceive. If you ponder it willingly and with pleasure, then it will conceive and give birth, and you will die.

Sermons 77A.3 ↗

Bede

Then desire, when it has conceived, gives birth to sin. And sin, when it is fully grown, brings forth death. Temptation occurs in three ways: by suggestion, by delight, by consent. By the suggestion of the enemy, and by delight or also by the consent of our frailty. But if, while the enemy suggests, we do not want to delight or consent to sin, this very temptation leads us to victory, by which we may deserve to receive the crown of life. …

Commentary on the Catholic Epistles ↗

Bonaventure

Concupiscence, when it has conceived, brings forth sin; and sin, when it is consummated, begets death. If, however, suggestion and delight stop short of consent, it is a venial sin. But if consent and action follow in those things which are prohibited by divine law, the sin is a consummated mortal sin. …

Breviloquium, Part 3, Chapter 8 ↗