John Calvin Commentary Genesis 49:21

"Naphtali is a hind let loose: He giveth goodly words." — Genesis 49:21 (ASV)

Naphtali. Some think that in the tribe of Naphtali speed is commended; I rather prefer another meaning, namely, that it will guard and defend itself by eloquence and graciousness of words, rather than by force of arms. It is, however, not an insignificant virtue to soothe ferocious minds and to appease excited anger by mild and gentle discourse, or, if any offense has been stirred up, to calm it by a similar method.

He therefore assigns this praise to the descendants of Naphtali, that they will rather seek to fortify themselves by kindness, by sweet words, and by the arts of peace, than by the defense of arms. He compares them to a hind let loose, which, having been taken in hunting, is not put to death but is instead cherished with delicacies.