Here is the last Song of Ascents. This psalm refers to priests who stood the night watch in the Temple. Their mission was not to guard the precincts; that was for the Levites assigned as Temple guards. Rather, the priestly duties were to keep alive praise and worship. We should assume they did this in some form of rotation, as the Hebrew people divided the hours of darkness into three watches.
In public worship, this would be rather like a benediction the worshipers would give to the night shift coming on duty at the end of the evening offering service. The actual time of day was more likely the afternoon prior to the common time of the evening meal. The worshipers would call for the priests on night shift with this little song and encourage them to take their job seriously.
We note in passing that the world translated here “bless” is a word that draws the image of humbling yourself before the Lord. It is the same word often used to indicate God’s response to that act of kneeling, His blessing to those who humble themselves from the heart. Thus, this psalm and this section of Psalms ends with a benediction upon those night watch priests and everyone whose heart remains behind in the Temple with them. Who would not so revere the maker of heaven and earth?