{Take heed, beware of the leaven of the Pharisees, and the
leaven of Herod} (Hor(8374)e, blepete apo t(8873) zum(8873) t(936e) Pharisai(936e)
kai t(8873) zum(8873) H(8872)(9369)dou). Present imperatives. Note apo and the
ablative case. Zum(885c) is from zumo(935c) and occurs already in  Mt
13:33  in a good sense. For the bad sense see  1Co 5:6 . He
repeatedly charged (diestelleto, imperfect indicative), showing
that the warning was needed. The disciples came out of a
Pharisaic atmosphere and they had just met it again at
Dalmanutha. It was insidious. Note the combination of Herod here
with the Pharisees. This is after the agitation of Herod because
of the death of the Baptist and the ministry of Jesus ( Mr
6:14-29  Mt 14:1-12  Lu 9:7-9 ). Jesus definitely warns the
disciples against "the leaven of Herod" (bad politics) and the
leaven of the Pharisees and Sadducees (bad theology and also bad
politics).