Atharva Veda 6.43: The same

For stranger and for friend alike this Darbha-grass removeth wrath.
Soother of Anger is it called because it calms the angry man.

This Plant that hath abundant roots spreads to the place where waters meet.
Soother of anger is the name Darbha-grass that springs from earth.

We draw thine obstinacy forth, set in thy mouth and in thy jaw: So dost thou yield thee to my will. to speak no more rebelli-ously.