R. Yochanan remarked, There is a small organ in man which satisfies him when in hunger and makes him hunger when he's satisfied, as it is said, "When they were starved they became full" (Hoshea 13:6)
R. Isaac said: A man's impulse to evil renews itself [in allure] every day, as is said, "Every impulse wrought by his mind was sheer evil every day" (Bereishit 6:5).
R. Simeon ben Lakish said: A man's impulse to evil grows in strength from day to day and seeks to slay him, as is said, "The wicked watch the righteous, and seek to slay him." (Tehillim 37:32)
And but for the Holy One who is his help, he could not withstand it, as is said, "Hashem will not leave him in his hand" (Tehillim 37:33)