What is the meaning of [No need of words, trust deeds]

“Actions may be, and indeed sometimes are deceptive in a measure though not as much so as words; and accordingly are received in general as more full and satisfactory proofs of the real disposition and character of persons than verbal expressions.”, Source for meaning, Porter, William Henry (1845). Proverbs; Arranged in Alphabetical Order …. Munroe and Company. p. 10.