Psalm 133 David is the author according to 18th-century theologian John Gill, David may have composed this psalm after he was unanimously crowned as king by the united tribes of Israel, or after his son Absalom’s revolt was put down and the tribes hurried to show their loyalty to David.This is a psalm that celebrates and praises the goodness and blessing of living together in unity. It is a song for going up to worship God in the Temple in Jerusalem. It compares unity to the precious oil that anoints Aaron the priest and the dew that refreshes Mount Hermon. It declares that God bestows his blessing and life on those who are united in his love in unity.
It reads in Psalm 133:1-3 NIV.
A song of ascents. Of David.
How good and pleasant it is when God’s people live together in unity! It is like precious oil poured on the head, running down on the beard running down on Aaron’s beard, down on the collar of his robe. It is as if the dew of Hermon were falling on Mount Zion. For there the Lord bestows his blessing, even life forevermore.