This psalm instructs us concerning a two-fold blessing: -

I.Our blessing God, that is, speaking well of him, which here we are taught to do, Psa 134:1, Psa 134:2. 1. It is a call to the Levites to do it. They were the servants of the Lord by office, appointed to minister in holy things; they attended the sanctuary, and kept the charge of the house of the Lord, Num 3:6, etc. Some of them did by night stand in the house of the Lord, to guard the holy things of the temple, that they might not be profaned, and the rich things of the temple, that they might not be plundered. While the ark was in curtains there was the more need of guards upon it. They attended likewise to see that neither the fire on the altar nor the lamps in the candlestick went out. Probably it was usual for some devout and pious Israelites to sit up with them; we read of one that departed not from the temple night or day, Luk 2:37. Now these are here called upon to blesss the Lord. Thus they must keep themselves awake by keeping themselves employed. Thus they must redeem time for holy exercises; and how can we spend our time better than in praising God? It would be an excellent piece of husbandry to fill up the vacancies of time with pious meditations and ejaculations; and surely it is a very modest and reasonable to converse with God when we have nothing else to do. Those who stood in the house of the Lord must remember where they were, and that holiness and holy work became that house. Let them therefore bless the Lord; let them all do it in concert, or each by himself; let them lift up their hands in the doing of it, in token of the lifting up of their hearts. Let them lift up their hands in holiness (so Dr. Hammond reads it) or in sanctification, as it is fit when they lift them up in the sanctuary; and let them remember that when they were appointed to wash before they went in to minister they were thereby taught to lift up holy hands in prayer and praise. 2. It is a call to us to do it, who, as Christians, are made priests to our God, and Levites, Isa 66:21. We are the servants of the Lord; we have a place and a name in his house, in his sanctuary; we stand before him to minister to him. Even by night we are under his eye and have access to him. Let us therefore bless the Lord, and again bless him; think and speak of his glory and goodness. Let us lift up our hands in prayer, in praise, in vows; let us do our work with diligence and cheerfulness, and an elevation of mind. This exhortation is ushered in with Behold! a note commanding attention. Look about you, Sirs, when you are in God's presence, and conduct yourselves accordingly.

II.God's blessing us, and that is doing well for us, which we are here taught to desire, Psa 134:3. Whether it is the watchmen's blessing their captain, or the Levites' blessing the high priest, or whoever was their chief (as many take it, because it is in the singular number, The Lord bless thee), or whether the blessing is pronounced by one upon many ("The Lord bless thee, each of you in particular, thee and thee; you that are blessing God, the Lord bless you"), is not material. We may learn, 1. That we need desire no more to make us happy than to be blessed of the Lord, for those whom he blesses are blessed indeed. 2. That blessings out of Zion, spiritual blessings, the blessings of the covenant, and of communion with God, are the best blessings, which we should be most earnest for. 3. It is a great encouragement to us, when we come to God for a blessing, that it is he who made heaven and earth, and therefore has all the blessings of both at his disposal, the upper and nether springs. 4. We ought to beg these blessings, not only for ourselves, but for others also; not only, The Lord bless me, but, The Lord bless thee, thus testifying our belief of the fulness of divine blessings, that there is enough for others as well as for us, and our good-will also to others. We must pray for those that exhort us. Though the less is blessed of the greater (Heb 7:7), yet the greater must be prayed for by the less.

Behold, bless ye the Lord, all ye servants of the Lord,.... All men are of right the servants of God being his creatures; and are under obligation, through his providential goodness, to bless and praise him; though they are not all in fact so: but all good men are, being made so by the power of divine grace; which frees them from the servitude of sin, Satan, and the world, and makes them willing to serve the Lord; as they do in righteousness and holiness, with reverence and godly fear, heartily and willingly, and with great pleasure; and yet have no dependence on any service they perform: and as these are under the highest obligations to bless the Lord; the is, to ascribe greatness to him, to give him the glory of his works, and thanks for his mercies, temporal and spiritual; so they do in this way, and for those things, bless and praise him, to which they are here excited;

which by night stand in the house of the Lord: according to Kimchi, these were the wise and holy men, that rose from their beds in the night, and went to pray in the temple, and to praise the Lord; and such a holy person was Anna, Luk 2:37; according to R. Obadiah and Arama, they were such who continued in the chambers of the temple in the night season to study in the law and in the expositions of it: but it is generally interpreted of the priests and Levites, who watched in the temple by night, that it might not be profaned nor plundered; and they were obliged to stand, for none might sit in the temple but a king of the house of David (d). The priests watched in three places, and the Levites in twenty one, according to the Jewish Misnah (e). The Targum is,

"who stand in the watch house of the sanctuary of the Lord, and praise in the nights;''

which was one part of their service, Ch1 9:33. Under the Gospel dispensation all the saints are priests, and they have a place in the house of the Lord; where they wait upon him in his ordinances, and serve him, and which they do continually. Some understand, by "nights", times of affliction, darkness, and desertion.

(d) Maimon. Beth Habbechirah, c. 7. s. 6. (e) Middot, c. 1. s. 1.