John Gill Commentary Genesis 34:13

"And the sons of Jacob answered Shechem and Hamor his father with guile, and spake, because he had defiled Dinah their sister," — Genesis 34:13 (ASV)

And the sons of Jacob answered Shechem and Hamor deceitfully ,
&c.] Proposing the marriage of their sister on terms after mentioned, when they never intended it should ever be: Onkelos, Jonathan, and Jarchi interpret it, "with wisdom", as if they answered wisely and prudently, but the word is never used in a good sense; and if it was wisdom, it was carnal wisdom and wicked cunning, and was disapproved of by plain hearted Jacob:

and said :
or spoke in this deceitful manner:

because he had defiled Dinah their sister ;
and therefore were filled with indignation at him, and fired with resentment against him, and vowed within themselves revenge upon him.