Imaam Ibn Hibbaan (rahimahullaah) said:
It is obligatory that the sensible person adheres to silence until he is obliged to speak (i.e. either by necessity or obligation), for there is a lot of regret when one speaks (unnecessarily) and less regret when one remains silence. The people with the longest misery and greatest affliction are those with an unrestricted tongue and a blind (or unconscious) heart.
[Source: Rawdatul Uqalaa’ page 43]