Verse 1-2
Psalms 134:1-2. Behold, bless ye the Lord, &c. — Attend to your duty, O ye ministers of the Lord; who not only by day, but by night also, reverently wait upon him in his house, 1 Chronicles 9:33. Employ your hearts and tongues in his praises, and cease not to declare how great and good he is.

Lift up your hands, &c. — Unto God, in prayer and praise; in the sanctuary — In that holy house of God where you stand; or, in holiness, as the margin reads it, and as is prescribed 1 Timothy 2:8. Do not therefore content yourselves with lifting up your hands, but see that this be done with pure and holy hearts. And bless the Lord — Be fervent and unwearied in your devotions and praises.

Verse 3
Psalms 134:3. The Lord that made heaven and earth — And therefore has all the blessings of both at his disposal, those of the upper and those of the nether springs; bless thee — O priest, who dost engage and encourage us in this blessed work; out of Zion — Where he dwells, and from whence he hears the prayers of his people, and gives them the blessings which they need.