In God's Word:
Psalm 134 is a learning tool for worship and even though it is short, only 3 verses, it is quite unique.
It is both a doxology (a form of words which ascribe praise to God) and a benediction (an utterance of good wishes or blessings). The doxology or greeting is in verses 1 and 2 and the blessing in verse 3.
While it is addressed to the Levite priests who stood guard by night at the temple, it has relevance to us today as well.