Note 117 — ACT I., SCENE I.
Reading edition
This phrase signifies take courage, or summon up resolution. It is at present always written in this manner; formerly it used, [very erroneously,] to be, take heart at grass; as in "Euphues," p. 18: "Rise, therefore, Euphues, and take heart at grasse, younger thou shalt never bee: plucke up thy stomacke, if love have stong thee, it shall not stifle thee."
Again, in Tarlton's "Newes out of Purgatory," p. 4: "Therefore taking heart at grasse, drawing more neere him," &c.
And Ibid., p. 24: "Seeing she would take no warning: on a day tooke heart at grasse, and belabour'd her well with a cudgel."