Our Gemara on amud aleph made an observation of the behavioral styles of the righteous versus the wicked, especially in terms of expressing and then following through with their commitments toward others: “The righteous say little and do much, whereas the wicked say much and do not do even a little.”

We can understand the wicked tend to over promise as they want to receive the admiration and appreciation in advance, without putting in the hard work. But, why is it a virtue for the righteous to “say little and do much”?  Would it not be just as exemplary to “say and do”, or even to “say much and do much”?

The Maharsha says the ethos of saying little is specific to the situation described in our gemara, of Avraham hosting guests.  The Tzaddik understates what he is offering so that the guests will feel comfortable, and once they are there, he gives them more.  “Stay for a bite to eat” is an easier way to convince the person to join you, even if you cooked a feast. Be’er Mayyim Chaim (Vayikra 13:9) offers an alternate explanation. It is simply hard to start things, so the righteous do not promise much, in case they cannot succeed in starting. Once they get into it, they are usually able to do far more, but they won’t know that until they get there.

An even more simple explanation that occurs to me, is that it is humble to refrain from saying much about intentions, and to let one’s hopefully successful actions speak for themselves. 

Psychologically speaking, when a person is overly affirmative about their intentions, it may be a reaction formation and betray ambivalence or conflict over it.  We find Gemaras where an overenthusiastic agreement is taken to actually signal misgivings and dissent, having halachic implications for determining intent in financial transactions (Bava Metzia 22a, “klach etzel yafos”). In addition, by engaging in a verbal fantasy about what the person promises to do, it discharges some of the psychic energy and motivation to do the work. The imagined achievement becomes a substitute for actual achievement.  When I was a child, my father Z”L used to say to me, “Don’t commit to a mitzvah too loudly, as the Satan will overhear and try to stop you.”  My father was being cute and accurate at the same time, he meant to say, the more you talk about it, the less you will tend to do it.   He would explain, don’t allow yourself the satisfaction of talking about it too much until after you achieve it, or you’ll get distracted in the day dreams of having accomplished it, when in actuality, as of yet, you did not.