From Faith Futures
Lüdemann [Jesus] (300f) notes the affinity with Sirach 27:7 (sic) and the saying of Jesus in Mark 7:15:
4 When a sieve is shaken, the refuse appears;
so do a person's faults when he speaks.
5 The kiln tests the potter's vessels;
so the test of a person is in his conversation.
6 Its fruit discloses the cultivation of a tree;
so a person's speech discloses the cultivation of his mind.
7 Do not praise anyone before he speaks,
for this is the way people are tested.
There is nothing outside a person that by going in can defile,
but the things that comes out are what defile.