Albert Barnes on Revelation 11:1

And there was given me. He does not say by whom, but the connexion would seem to imply that it was by the angel. All this is of course to be regarded as symbolical. The representation undoubtedly pertains to a future age, but the language is such as would be properly addressed to one who had been a Jew, and the imagery employed is such as he would be more likely to understand than any other. The language and the imagery are, therefore, taken from the temple, but there is no reason to suppose that it had any literal reference to the temple, or even that John would so understand it. Nor does the language here used prove that the temple was standing at the time when the book was written; for as it is symbolical, it is what would be employed whether the temple were standing or not, and would be as likely to be used in the one case as in the other. It is such language as John, educated as a Jew, and familiar with the temple worship, would be likely to employ if he designed to make a representation pertaining to the church.

A reed--καλαμος. This word properly denotes a plant with a jointed hollow stalk, growing in wet grounds. Then it refers to the stalk as cut for use, as a measuring-stick, as in this place; or a mock sceptre, Mt 27:29-30; or a pen for writing, 3Jn 1:13. Here it means merely a stick that could be used for measuring.

Like unto a rod. This word--ραβδος--means properly a rod, wand, staff, used either for scourging, 1Cor 4:21; or for leaning upon in walking, Mt 10:10; or for a sceptre, Heb 1:8. Here the meaning is, that the reed that was put into his hands was like such a rod or staff in respect to size, and was therefore convenient for handling. The word rod also is used to denote a measuring-pole, Ps 74:2, Jer 10:16, 51:19.

And the angel stood, saying. The phrase, "the angel stood," is wanting in many MSS. and editions of the New Testament, and is rejected by Professor Stuart as spurious. It is also rejected in the critical editions of Griesbach and Hahn, and marked as doubtful by Tittmann. The best critical authority is against it, and it appears to have been introduced from Zech 3:5. The connexion does not demand it, and we may, therefore, regard the meaning to be, that the one who gave him the reed, whoever he was, at the same time addressed him, and commanded him to take a measure of the temple and the altar.

Rise, and measure the temple of God. That is, ascertain its true dimensions with the reed in your hand. Of course, this could not be understood of the literal temple--whether standing or not--for the exact measure of that was sufficiently well known. The word, then, must be used of something which the temple would denote or represent, and this would properly be the church, considered as the abode of God on the earth. Under the old dispensation, the temple at Jerusalem was that abode; under the new, that peculiar residence was transferred to the church, and God is represented as dwelling in it. 1Cor 3:16. Thus the word is undoubtedly used here, and the simple meaning is, that he who is thus addressed is directed to take an accurate estimate of the true church of God; as accurate as if he were to apply a measuring-reed to ascertain the dimensions of the temple at Jerusalem. In doing that, if the direction had been literally to measure the temple at Jerusalem, he would ascertain its length, and breadth, and height; he would measure its rooms, its doorways, its porticoes; he would take such a measurement of it that, in a description or drawing, it could be distinguished from other edifices, or that one could be constructed like it, or that a just idea could be obtained of it if it should be destroyed. If the direction be understood figuratively, as applicable to the Christian church, the work to be done would be to obtain an exact estimate or measurement of what the true church was--as distinguished from all other bodies of men, and as constituted and appointed by the direction of God; such a measurement that its characteristics could be made known; that a church could be organized according to this, and that the accurate description could be transmitted to future times. John has not, indeed, preserved the measurement; for the main idea here is not that he was to preserve such a model, but that, in the circumstances, and at the time referred to, the proper business would be to engage in such a measurement of the church that its true dimensions or character might be known. There would be, therefore, a fulfilment of this, if at the time here referred to there should be occasion, from any cause, to inquire what constituted the true church; if it was necessary to separate and distinguish it from all other bodies; and if there should be any such prevailing uncertainty as to make an accurate investigation necessary.

And the altar. On the form, situation, and uses of the altar, Mt 5:23-24; 21:12. The altar here referred to was, undoubtedly, the altar situated in front of the temple, where the daily sacrifice was offered. To measure that literally, would be to take its dimensions of length, breadth, and height; but it is plain that that cannot be intended here, for there was no such altar where John was, and, if the reference were to the altar at Jerusalem, its dimensions were sufficiently known. This language, then, like the former, must be understood metaphorically, and then it must mean--as the altar was the place of sacrifice--to take an estimate of the church considered with reference to its notions of sacrifice, or of the prevailing views respecting the sacrifice to be made for sin, and the method of reconciliation with God. It is by sacrifice that a method is provided for reconciliation with God; by sacrifice that sin is pardoned; by sacrifice that man is justified; and the direction here is equivalent, therefore, to a command to make an investigation on these subjects, and all that is implied would be fulfilled if a state of things should exist where it would be necessary to institute an examination into the prevailing views in the church on the subject of the atonement, and the true method of justification before God.

And them that worship therein. In the temple; or, as the temple is the representation here of the church, of those who are in the church as professed worshippers of God. There is some apparent incongruity in directing him to "measure" those who were engaged in worship; but the obvious meaning is, that he was to take a correct estimate of their character; of what they professed; of the reality of their piety; of their lives, and of the general state of the church considered as professedly worshipping God. This would receive its fulfilment, if a state of things should arise in the church which would make it necessary to go into a close and searching examination on all these points, in order to ascertain what was the true church, and what was necessary to constitute true membership in it. There were, therefore, three things, as indicated by this verse, which John was directed to do, so far as the use of the measuring-rod was concerned:

(a) to take a just estimate of what constitutes the true church, as distinguished from all other associations of men;

(b) to institute a careful examination into the opinions in the church on the subject of sacrifice or atonement--involving the whole question about the method of justification before God; and

(c) to take a correct estimate of what constitutes true membership in the church; or to investigate with care the prevailing opinions about the qualifications for membership.

(a) "reed" Rev 21:15, Zech 2:1 (b) "measure" Eze 40:1-Eze 48:35