Albert Barnes Commentary Matthew 10:16

"Behold, I send you forth as sheep in the midst of wolves: be ye therefore wise as serpents, and harmless as doves." — Matthew 10:16 (ASV)

As sheep in the midst of wolves. That is, I send you, inoffensive and harmless, into a cold, unfriendly, and cruel world. Your innocence will not be a protection.

Be wise as serpents, etc. Serpents have always been an emblem of wisdom and cunning (Genesis 3:1). The Egyptians used the serpent in their hieroglyphics as a symbol of wisdom. Probably the specific way Christ directed His followers here to imitate the serpent was in its caution in avoiding danger. No animal equals them in the rapidity and skill they demonstrate in escaping danger.

So Christ said to his disciples, "You need caution and wisdom in the midst of a world that will seek your lives." He also directs them to be harmless, not to provoke danger, not to do injury, and thus make their fellow men justly enraged against them.

Doves are, and always have been, a striking emblem of innocence. Most people would foolishly destroy a serpent, however harmless it may be; yet few are so hard-hearted as to kill a dove.