A.T. Robertson Commentary Luke 6:45

"The good man out of the good treasure of his heart bringeth forth that which is good; and the evil [man] out of the evil [treasure] bringeth forth that which is evil: for out of the abundance of the heart his mouth speaketh." — Luke 6:45 (ASV)

Bringeth forth (προφερε). In a similar saying repeated later. Matthew 12:34f. has the verb εκβαλλε (throws out, casts out), a bolder figure. "When men are natural, heart and mouth act in concert. But otherwise the mouth sometimes professes what the heart does not feel" (Plummer).