Remigius of Auxerre
Catena Aurea · Matthäusevangelium 10
Behold, I send you forth as sheep in the midst of wolves: be ye therefore wise as serpents, and harmless as doves. But beware of men: for they will deliver you up to the councils, and they will scourge you in their synagogues; And ye shall be brought before governors and kings for my sake, for a testimony against them and the Gentiles.
The Lord unites these two things; because simplicity without wisdom might be easily deceived, and wisdom is dangerous unless it be tempered with simplicity that does no man hurt.