Every plant, &c.— Every plantation, Φυτεια, that is to say, doctrine. The metaphor was familiar in the time of our Lord, and is still used by the Jewish writers, with whom to pull up plantations signifies "to deny articles of faith." See Heylin and Wetstein.
Related Commentaries of Matthew 15:13
Matthew 15:13
13 But he answered and said,Every plant, which my heavenly Father hath not planted, shall be rooted up.