Psalms 133 - G. Campbell Morgan's Exposition on the Whole Bible

At last the pilgrims are within the city. After the long and toilsome march their feet actually stand within the city of God. The common impulse of all has been the desire to reach the dwelling-place of Jehovah, and to worship before His face. This desire has brought them together, and in this nearness of souls gathered by a common purpose there is a new blessing, and of that they sing. In finding Jehovah they have found each other, and as a result of common loyalty to Him, a new social order has been created.

Under two figures the singer describes the blessedness of this order. It is like the holy anointing oil. It is like the dew of Hermon. The former suggests joy and richness of experience. The latter describes the freshness of renewal of all life. The source of the new joy is recognised, “Jehovah commanded the blessing.” The first matter of importance in individual life is ever that of seeking fellowship with God. When this is sought and found, there always follows the realisation of the fellowship of the saints. All lack of union among ourselves is due to failure to realise our union with God.