Psalm 134 is a blessing which goes two ways. It begins with a call upon the worshipers to bless God, and ends with a blessing for the worshipers themselves.
V. 2 says, “Lift your hands toward the sanctuary and bless the LORD. ”
1b-2. Summons to praise/bless
The underlying structure of Psalm 134 is the parallel blessings: the people are exhorted to bless (barakhu) God, and God is called upon to bless (yevarekhekha) the people. The psalm is very short, only 23 words (counting all Hebrew morphemes), but mentions God’s name five times. It is the last psalm in the shir hama’alot section, indicating that it was possibly said to the pilgrims who journeyed to Jerusalem.
The summons to praise is directed to the “servants (‘avdei) of the LORD who stand (ha’omedim) nightly in the house of the Lord,” and it probably refers to the community at large (cf. Ps. 79:10, 90:16, etc.). Alternatively, it might be referring to the priests or Levites (cf. Deut 10:8 and 18:7 for descriptions of their “standing” and “blessing”). Nightly hymn singing is attested to in Isa. 30:29: “For you, there shall be singing As on a night when a festival is hallowed; There shall be rejoicing as when they march With flute, with timbrels, and with lyres To the Rock of Israel on the Mount of the LORD.”
The final section of the psalm is a blessing for the worshippers themselves. The phrase “May the LORD bless you” is found in two contexts: (a) cultic blessings (e.g. Num. 6:24, Ps. 128:5), and (b) greetings between two people (e.g. Ruth 2:4, Ps. 129:8). This indicates that the phrase had two uses, as a day-to-day greeting and a ceremonial blessing. It also occurs quite often in Deuteronomy (e.g. 14:29, 15:4, 16:15, etc.).
V. Important Verses
vv. 1-2 “Now bless the LORD, all you servants of the LORD who stand nightly in the house of the LORD. Lift your hands toward the sanctuary and bless the LORD.”