What is the name of the scholar whose name was used as a simile for abstinence?

[PleaseHelpmeOut]

Recently, I have been trying to recall the name of a scholar from a particular folktale/legend.
There was a scholar who lent his shirt? to a girl and let her stay in his room for one night without touching her or doing anything inappropriate. 

Because of that incident, people used his name as a simile in Chinese language.
“ acting like <that scholar’s name> “ means that you are very good at abstinence? 
 

So my question is what is that scholar’s name? 
This has been bugging me for a while. His name is just at the tip of my tongue, but I couldn’t recall it! I tried googling, but it didn’t work.

Also, if anyone has a link to a website about that tale, please share with me. I don’t remember much about the tale and would love to read it again.

please, help me out. ?

 

 

[阿季福]

柳下惠，这个典故叫“坐怀不乱”。

[tsitsi]

Just heard 柳下惠 in a drama yesterday