Matthew Henry Commentary Zechariah 2:1-5

"And I lifted up mine eyes, and saw, and, behold, a man with a measuring line in his hand. Then said I, Whither goest thou? And he said unto me, To measure Jerusalem, to see what is the breadth thereof, and what is the length thereof. And, behold, the angel that talked with me went forth, and another angel went out to meet him, and said unto him, Run, speak to this young man, saying, Jerusalem shall be inhabited as villages without walls, by reason of the multitude of men and cattle therein. For I, saith Jehovah, will be unto her a wall of fire round about, and I will be the glory in the midst of her." — Zechariah 2:1-5 (ASV)

The Son of David, that is, the Man Christ Jesus, whom the prophet sees with a measuring line in His hand, is the Master-Builder of His church. God notices the extent of His church and will take care that whatever number of guests are brought to the wedding supper, there will be room. This vision means well for Jerusalem.

The walls of a city, while they defend it, also restrict its inhabitants; but Jerusalem will be extended as freely as if it had no walls at all, yet it will be as safe as if it had the strongest walls. In the church of God, there is still room for other multitudes, more than humans can number. No one will be refused who trusts in Christ; and He never shuts out from heaven one true member of the church on earth.

God will be a Wall of fire around them, which can neither be broken through nor undermined, nor can it be assailed without danger to those who attack it. This vision was to reach its full accomplishment in the gospel church, which is extended by admitting the Gentiles into it, and which has the Son of God as its Prince and Protector, especially in the glorious times yet to come.