Genesis 49:21

Naphatali is a swift messenger, like a hind that runneth on the tops of the mountains, bringing good tidings: he it was who announced that Joseph was living; he it was who hasteneth to go into Mizraim, and bring the contract of the double field in which Esau had no portion; and when he shall open his mouth in the congregation of Israel to give praise, he shall be the chosen of all tongues.

NAPHTALI IS A HIND SENT FORTH. It was a custom among the rulers of countries to send hinds to one another, and this was the manner in which it was done: Hinds which were born in the territory of the king of the north country would be raised in the palaces of the king of the south country. They would attach a written message to its horns, and it would run speedily and return to its original habitat, and in this way the king of the north country would be apprised of the news. This is the meaning of the phrase, He giveth goodly words, meaning that he is a dispatched hind sent who bears good tidings.
This practice is known, and it is mentioned in the Jerusalem Talmud, in Tractate Shevi’ith: “They said, ‘If they go they will return, and if you wish to prove it, bring deer and send them to a land far away, and in the end they will return.’ He did so. He brought deer and covered their horns with silver and sent them to Africa, and at the end of thirteen years they returned to their place.” That is, they freed them after thirteen years, and they returned at once. The analogy is that Naphtali is satisfied with favor, and full with all good things, and from him tidings will come forth to all Israel that his land has produced fruits abundantly, even as our Rabbis have mentioned concerning the fruits of Gennesareth.

אילה שלוחה, his soldiers were as fleet-footed as gazelles. In Chronicles I 12,9 this is described as Naftali being כצבאים על ההרים למהר , “as speedy as the deer on the mountains.”

הנותן אמרי שפר. When they would return from battle, they would be the bearers of happy tidings, being the first to announce the victory won by the Jewish armies. The word שפר, is a derivative of שופר, the ram’s horn; they would announce the good news by means of the appropriate blasts of the shofar. We have some proof of this in Judges 5,18 where Devorah in her victory song speaks of זבלון עם חרף נפשו למות, ונפתלי על מרומי שדה, “Zevulun is a people that mocked at death, and Naftali-on the open heights.” [they were the only two tribes that heeded Barak’s and Devorah’s call to do battle against Siserah, the commander of the Canaanite armies of King Yavin whose army was equipped with 900 armoured vehicles. Ed.]

נפתלי אילה שלוחה, Yaakov prophesied regarding the extraordinary salvation which would accrue to Israel thanks to a single man from the tribe of Naftali, Barak, the commander of the forces who defeated Siserah at the river Kishon, putting to flight an army boasting 900 armoured vehicles. Seeing that he would be assisted by the prophetess Devorah, his being fleet-footed is not credited only to him, and the word describing this is in the feminine gender, ayalah, instead of ayal. Barak had refused to attack unless Devorah would be with him. This is also why Yaakov said שלוחה, again in the feminine mode, to allude to Devorah’s role in the battle. It sounds as if Devorah had been dispatched by G’d to hasten Barak’s coming to a decision, seeing he had been so hesitant to join battle with Siserah. Concerning the song of thanksgiving composed by Devorah after that battle (Judges chapter 5), Yaakov describes that song as אמרי שפר,”words of beautiful poetry.”

נפתלי אילה שלוחה, “Naftali (its territory) is (like) a free running doe;” its territory produces fruit that ripens easily and quickly, as if it had been chased and tries to escape the net it has fallen into.(B‘reshit Rabbah 99,12)

הנותן אמרי שפר, “he conveyed pleasant messages.” It thanked the Lord for having saved it from death after being hunted. Yaakov now refers to him in the masculine mode, perhaps because the doe is usually referred to in the masculine mode in other languages. Another interpretation: the subject here is Naftali himself, and refers to Naftali giving thanks to his Creator for having been given the chance to escape the net. Still another interpretation: the territory of Naftali can be compared to that of a doe after it had been skinned, its skin not having stuck to its flesh so that it could be put to good use while still intact. (Compare Leviticus 1,6) The word שלוחה, may refer what the Talmud describes as the reason why the land of Israel is known as ארץ צבי, “the land of the antelope,” namely produces fruit in such large quantities that it cannot be hidden. (Talmud tractate Ketuvot folio 112, i.e. “its flesh cannot be hidden completely once its skin had been flayed). The word שלוחה may be understood as in Song of Songs 4,14, “your arid areas”) i.e. even the relatively arid areas in its territory are extremely fruitful. The word אמרי in this verse may be understood as in Isaiah 17,6: שנים, שלושה גרגרים בראש אמיר , “two even three berries on the topmost branch.”