Commentary on Avos 1:17

The Maharal writes, “The point is that taking into account that a person is a physical being, he gains from silence. Speaking is... a physically based power. Speech is a physical attribute, not a mental one at all. For that reason, speech should be shunned so as not to suffer from an error or mental disintegration. When a person is involved in verbal activity, he is negating his mental resources… One should, therefore [try to] maintain silence and take initiatives with his intellectual features that are not corporeal, as is the power of speech, thus avoiding errors.” (AbsoluteTruth613.blogspot.com)