I will also gather. Compare Zechariah 14:2-4.
all nations. Put by Figure of speech Synecdoche (of the Whole), App-6, for representatives or people from all nations.
the valley of Jehoshaphat. Between Jerusalem and the Mount of Olives. The name then existing is still preserved in the village of Sh'afat; now the Wady Sidi Miriam and Wady Far'aun. Mentioned only here, and in Joel 3:12. the event recorded in 2 Chronicles 20:21-26 being typical of this scene of the future judgment of the nations. Note "to this day".
Jehoshaphat. Jehovah hath judged.
will plead with them. will judge them. Note the Figure of speech Paronomasia (App-6) for emphasis. Hebrew. yehoshaphat vnishpatti. Compare Isaiah 66:16; Ezekiel 38:22.
My. Note the force of this pronoun when Jehovah calls Israel again "Ammi" (Hosea 2:23). The judgment of Matthew 25 turns on how the nations had treated "My brethren", and not upon the grounds of justification by faith.
My heritage. Reference to Pentateuch (Deuteronomy 32:9). App-92. Israel. Note this; not merely Judah, but the twelve-tribed nation.