And the sons of Jacob answered Shechem and Hamor his father deceitfully, and said, because he had defiled Dinah their sister:

Jamieson-Fausset-Brown Bible Commentary

13. The sons of Jacob answered-The honor of their family consisted in having the sign of the covenant. Circumcision was the external rite by which persons were admitted members of the ancient Church. But that outward rite could not make the Shechemites true Israelites; and yet it does not appear that Jacob's sons required anything more. Nothing is said of their teaching the people to worship the true God, but only of their insisting on their being circumcised; and it is evident that they did not seek to convert Shechem, but only made a show of religion-a cloak to cover their diabolical design. Hypocrisy and deceit, in all cases vicious, are infinitely more so when accompanied with a show of religion; and here the sons of Jacob, under the pretense of conscientious scruples, conceal a scheme of treachery as cruel and diabolical as was, perhaps, ever perpetrated.

Matthew Henry's Concise Commentary

34:1-19 Young persons, especially females, are never so safe and well off as under the care of pious parents. Their own ignorance, and the flattery and artifices of designing, wicked people, who are ever laying snares for them, expose them to great danger. They are their own enemies if they desire to go abroad, especially alone, among strangers to true religion. Those parents are very wrong who do not hinder their children from needlessly exposing themselves to danger. Indulged children, like Dinah, often become a grief and shame to their families. Her pretence was, to see the daughters of the land, to see how they dressed, and how they danced, and what was fashionable among them; she went to see, yet that was not all, she went to be seen too. She went to get acquaintance with the Canaanites, and to learn their ways. See what came of Dinah's gadding. The beginning of sin is as the letting forth of water. How great a matter does a little fire kindle! We should carefully avoid all occasions of sin and approaches to it.