They shall walk after the Lord - Not only would God not destroy them all, but a remnant of them should “walk after the Lord,” i. e., they shall believe in Christ. The Jews of old understood this of Christ. One of them saith , “this pointeth to the time of their redemption.” And another , “Although I will withdraw from the midst of them My divine presence for their iniquity, and remove them out of their own land, yet shall there be a long time in which they shall seek after the Lord and find Him.” This is what Hosea has said before, that they should “abide many days without a king and without a prince, and without a sacrifice; afterward shall the children of Israel return and seek the Lord their God, and David their king” Hosea 3:4-5. : “Whereas now they “fled from” God, and “walked after other gods after the imagination of their evil hearts, after their own devices” Hosea 7:13; Jeremiah 7:9; Jeremiah 3:17; Jeremiah 18:12, then he promises, they shall “walk after God the Lord,” following the will, the mind, the commandments, the example of Almighty God. As God says of David, He “kept My commandments, and walked after Me with all his heart” 1 Kings 14:8; and Micah foretells that “many nations shall say, we will walk in His paths” Micah 4:2. They shall “follow after” Him, whose infinite perfections none can reach; yet they shall “follow after,” never standing still, but reaching on to that which is unattainable by His grace, attaining the more by imitating what is inimitable, and stopping short of no perfection, until, in His presence, they be perfected in Him.
He shall roar like a lion - Christ is called “the Lion of the tribe of Judah” Revelation 5:5. His “roaring” is His loud call to repentance, by Himself and by His Apostles. The voice of God to sinners, although full of love, must be full of awe too. He calls them, not only to flee to His mercy, but to “flee from the wrath to come.” He shall call to them with a voice of Majesty command.
When He shall roar, the children shall tremble from the West - that is, they shall come in haste and fear to God. “His word is powerful, sharper than any two-edged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow” Hebrews 4:12. Whence those whose hearts were pricked at the preaching of Peter, said to him with trembling, “Men and brethren what shall we do?” Acts 2:37. So did the preaching of judgment to come terrify the world, that from all places some did come out of the captivity of the world and did fly to Christ” . He says, “from the West;” for “from the West” have most come in to the Gospel. Yet the Jews were then about to be carried to the East, not to the West; and of the West the prophets had no human knowledge. But the ten tribes, although carried to the East into Assyria, did not all remain there, since before the final dispersion, we find Jews in Italy, Greece, Asia Minor; where those who had been restored to their own land, would not have anew exiled themselves. In these, whenever they were converted, this prophecy was fulfilled.