“Now praise the Lord , all you servants of the Lord who stand in the Lord ’s house at night! Lift up your hands in the holy place and praise the Lord! May the Lord , Maker of heaven and earth, bless you from Zion.” Psalms 134:1‭-‬3

Psalm 134 is the 2nd shortest of the psalms, with only 3 verses.

The writer gets straight to the point. “Now praise the Lord, all you servants of the Lord who stand in the Lord ’s house at night”. When it was fully functional, the tabernacle/temple worship center was fully staffed and employed priests to worship, sing, offer sacrifices and service the temple in shifts, day and night, 24/7. Temple upkeep and priestly service was the original function and role of the Levites. The picture of this psalm is of that priest, hands uplifted, softly offering prayers and incense to God in the “holy place” the middle section of the tabernacle or temple. The holy place was an exclusive section of the temple/tabernacle. It was reserved for priests or men, functioning in a priestly role of interceeding for his family.
These men, first of all had to be sin free, meaning that they had stopped at the altar to make a sacrifice for their sins. They had to be completely clean, which meant that they had stopped at the laver, examining and washing themselves of any spot or blemish that they might have sustained while sacrificing their offering or that may have been brought in with them. They wore clean, sometimes new clothes. Every aspect of their being had to be clean, pure and forgiven.
David tells these priests to praise God with all of their heart and with their hands lifted high, even in the night watches, when no one else would see them.

David ends the psalm by asking God to bless these priests for their service.

Jesus, our High Preist, has once for all, paid for all our sins with His own blood. WE NO LONGER NEED TO OFFER SACRIFICES! We have EVERY reason to praise God with our whole heart, even when its dark and no one else is there!

Think about it!