In two occasions, one admitting the righteousness of Tamar (Gen 38:26), and the other a selfless desire to sacrifice for his brother Benjamin (Gen 44:33).
Some repent out of selfish desires: to gain acceptance, to be counted as virtuous as others, to be ahead of others in the 'competition' of righteousness, to be at peace with their guilt, etc.
A true repent mortifies one's own body of sins.