Superspeed of Naphtali

Question

Why did Yaakov bless Naphtali with speed? And why him? Moreover, in two cases that I know of - with Eisav (how the funeral of Jacob described in midrash, that Naphtali was sent to bring sales document) and in Egypt (it's in midrash too, start of Vaigash, that Judah sent Naphtali to see how many markets are in Egypt to destroy all the country if Yosef didn't free Binyomin) - in fact, his speed did not help.

UPD: now I understand, that Naphtali already had the speed before the blessings. But the question is still there: why exactly Naphtali and for what G-d gave him that power?

Answer 1

The bracha is Vay'chi 49:21

נַפְתָּלִי אַיָּלָה שְׁלֻחָה הַנֹּתֵן אִמְרֵי שָׁפֶר:

Rav Hirsch says on that pasuk, that the characteristic of Naftali is

what one entrusts Naphtali to do, will be speedily carried out. Naphtali does not act on his own initiative, is not self-productive, but what others have decided for the benefit of the community he quickly adopts and quickly carries out.

and

Neither for deed nor for thought is Naphtali original. But he knows how to adopt the thoughts of others happily bot for deed and speech, knows how to carry them out speedily and present them beautifully.

Thus we see that his speed is to carry out the requests of his brothers. In the case of Eisav that you mention, this speed was still not the appropriate reaction, since Chushim son of Dan was able to act in a more appropriate manner to short circuit the lawfare that Eisav attempted to use to prevent the burial of Yaakov.

Answer 2

The prompt for the question appears to be the pasuk in parashat Vaychi, that is, Bereishit 49:21.

נַפְתָּלִי אַיָּלָה שְׁלֻחָה הַנֹּתֵן אִמְרֵי שָׁפֶר

The idea that this refers to extreme swiftness of the person Naftali can be found in a midrash appearing in Sotah 13a, and the first part of the midrash is cited by Rashi on the pasuk. The gemara reads, in part:

They replied to him, 'The document is in the land of Egypt. Who will go for it? Let Naphtali go, because he is swift as a hind'; for it is written: Naphtali is a hind let loose, he giveth goodly words10 — R. Abbahu said: Read not 'goodly words' (imre shefer) but imre sefer (words of a document). Among those present was Hushim, a son of Dan, who was hard of hearing; so he asked them, 'What is happening?' They said to him, '[Esau] is preventing (the burial) until Naphtali returns from the land of Egypt'. He retorted: 'Is my grandfather to lie there in contempt until Naphtali returns from the land of Egypt!' He took a club and struck (Esau) on the head so that his eyes fell out and rolled to the feet of Jacob. Jacob opened his eyes and laughed; and that is what is written: The righteous shall rejoice when he seeth the vengeance; he shall wash his feet in the blood of the wicked.

That is, the words of the blessing to Naftali are interpreted, out of context, to mean:

נַפְתָּלִי אַיָּלָה שְׁלֻחָה = Naftali is very fast הַנֹּתֵן אִמְרֵי שָׁפֶר = he will bring the words of the scroll

Nothing in this midrash indicates that Yaakov miraculously granted Naftali super speed with his blessing. Rather, the brothers, using Yaakov's words, are saying that Naftali is very swift, and therefore, he should bring the scroll.

Indeed, the other midrash, about the confrontation with Yosef, also based on the words נַפְתָּלִי אַיָּלָה שְׁלֻחָה, describes Naftali as very swift. This was not a result of Yaakov's blessing, for it occurred well before Yaakov's blessing. And other descendants of Yaakov, in that midrash, have other superpowers. For instance, the ability to shout and shatter all the teeth of the Egyptians; to roar and have chest hairs pierce through one's shirt like iron nails; to kick a boulder and have it shatter; to restrain Shimon.

If so, the easy answer is that Yaakov gave him that descriptive blessing because, of the various brothers, he in fact possessed that super speed.

By the way, Rashi on the verse (linked above) mentions this midrash as a matter of midrash, but takes the simple peshat meaning to be that if refers either to the quality of their land inheritance or to to future events regarding the tribe of Naftali. Thus:

a swift gazelle: This is the valley of Gennesar, which ripens its fruits swiftly, like the gazelle, which runs swiftly. אַיָלָה שְׁלֻחָה means a gazelle that runs swiftly. — [from Gen. Rabbah 99:12]

[he is one] who utters beautiful words: As the Targum renders. [See below.] Another explanation: A swift gazelle: He (Jacob) prophesied concerning the war with Sisera: “and take with you ten thousand men of the men of Naphtali, etc.” (Jud. 4:6), and they went there with alacrity. And so it is stated there with an expression of dispatching, “into the valley they rushed forth with their feet” (ibid. 5:15).