The tzadik is someone who knows when to give and when not to give:
the one who can be the generous provider of the people, and the one who can also withstand the temptation either to bestow good or to refrain from giving.
The capacity to control one's natural propensities is one of the main characteristics of the tzadik and makes it possible for him to be that strangely double personality, saint and ruler.
Every tzadik is in a way both saint and sovereign, not only able to resist temptation but also capable of boundless giving as an act of grace as well as of control over all manner of situations.
–Rabbi Adin Steinsaltz
From "Joseph," in Biblical Images by Rabbi Adin Steinsaltz