Genesis 49:16

From the house of Dan there is to arise a man who will judge his people with the judgment of truth. All the tribes of Israel will hearken to him together.

DAN SHALL JUDGE ‘YADIN’ HIS PEOPLE. This has the same meaning as in the verse, For the Eternal ‘yadin’ His people, which Onkelos translates as, “For the Eternal will judge the judgment of His people,” just as in the expressions: Be thou my judge, O G-d, and plead my cause against an ungodly nation; The cause of the widow. (plead for the widow), which means rivu riv almanah (plead the plea of the widow). Here, likewise, the sense of the verse is: “Dan will judge the judgment of his people.” (T’chelet Mordechai. See my Hebrew commentary, p. 270, Note 39.) The verse is thus stating that Dan will avenge the cause of his people, all the tribes of Israel, as one. And the purport of it is as follows: The Philistines wronged all Israel many times. In the days of Shamgar the son of Anath they began their oppression of Israel, and in the days of Jephthah it is written, And He gave them over into the hand of the Philistines,, 10:7. and after the days of Abdon the son of Hillel,, 12:13. it is also written, And the Eternal delivered them into the hand of the Philistines forty years., 13:1. There was none among the Judges who subdued them or had any victory at all over them. Now although it is written concerning Shamgar, And he smote the Philistines six hundred men with an ox-goad, this was not “vengeance,” relatively speaking, as it was not a great slaughter. This is why it is written concerning Samson, And he shall begin to save Israel out of the hand of the Philistines, and he avenged the cause of Israel from them for he slew many people and killed all the lords of the Philistines., 16:27 and 30. Scripture mentions yadin (he will judge), since this avenger was a judge, not a king. It is possible that this interpretation coincides with the opinion of Onkelos, who translated: “In his days his people will be delivered.” as meaning “will avenge.” See also my Hebrew commentary, p. 270.
It is possible that the expression, as one of the tribes of Israel, means “as the outstanding one of the tribes,” namely, Judah, concerning whom it is said, Thy hand shall be on the neck of thine enemies, thus implying that this one also will be victorious over his enemies and subdue them.

דן ידין עמו, those who explained this as a reference to Shimshon, one of the judges of Israel, have read the text only superficially. Did they really think that Yaakov, on his deathbed, would prophesy concerning a single specific individual who, moreover, fell into the hands of the Philistines and ended his life as their victim? Far be it from Yaakov to focus on such events at a time like this, even if he foresaw it! Yaakov relates to the tribe of Dan who is described as the rearguard of the Jewish armies in the desert both in Numbers 10,25 and in the Book of Joshua 6,9 where this tribe is described in identical terms. The fact that the rearguard is the most exposed section of the army which has to beat off any attacks from the rear, means that it needs extra protection by G’d. Yaakov says that he will enjoy success in avenging any unprovoked attacks on the Jewish people, i.e. their army. The words

כאחד שבטי ישראל, describe this tribe’s warding off such attacks, similar to what Moses said in Deuteronomy 32,36 כי ידון ה' עמו, or in Deut. 32,43 דם עבדיו יקום ונקם ישיב לצריו. “He will avenge the blood of His people, for He will wreak vengeance on his foes.” David expresses similar feelings in Psalms 110,6 when he says:ידיו בגויים מחץ גוויות מחץ ראשו על ארץ רבה, ”He works judgment on the nations, heaping up bodies, crushing heads far and wide.”

דן ידין עמו, Yaakov predicts that a judge will emerge from among the Danites as, or equal to, any of the other tribes of Israel. The reason why Yaakov had to make such a strange sounding comment was that Dan was a son of Rachel’s maid, Bilhah, and the status of the descendants of the maidservants of the matriarchs might have been questioned. Yaakov wants it understood that there is not going to be such a relationship between his sons. To emphasise this, Moses appointed the tribe of Dan as one of the four tribes who were leaders of their respective army corps comprising three tribes each. (compare Numbers 2,25) The judge from the tribe of Dan who presided over the court was Shimshon, of whom we are told in Judges 16,31 that he judged the people for 20 years.