Genesis 19:35

35.And the younger arose, and lay with him. This place teaches us how dangerous it is, to fall in the snares of satan. For, who once is caught therein, involves himself deeper and deeper in it. It is sure that Lot has been a modest man, but either, that the daughters have overtaken him while he was overcome with sadness, or that he allured by any other means to excessive drinking, once being decayed to excessiveness, he is again deceived the next day. We must therefore diligently resist the first beginning, for it is nearly impossible that they, who are once stupefied through its sweetness, totally lose themselves in the vices. Therefore, men ought to be on their guard against stimulus to evil, as deadly evils; and men ought to fear each flattering temptation as something poisonous. And this circumstance deserves attention, that Lot, among the Sodomites by the accumulation of crimes which nearly defiled heaven and earth, was chaste and clean, like an angel.

Whence did he keep such a cleanness in Sodom, else then through the knowledge of the evil, that surrounded him, which made him worried and careful? Presently, being safe on the mountain, satan besieges him with new pitfalls. Through this example, the Spirit admonishes us to watchfulness, that, when we think the least about it, an invisible enemy stretches snared for us. Likewise has Moses told earlier that Adam was deceived in Paradise. When we take care for ourselves, that will that watchfulness make us being on our guard against all guiles of our enemy. For there is nobody who not carries with him thousands of temptation to his own deceit.