Jamieson, Fausset & Brown

Lord JEHOVAH--Hebrew, Jah, Jehovah. The union of the two names expresses in the highest degree God's unchanging love and power (compare Psa 68:4). This passage, and Isa 12:2; Exo 6:3; Psa 83:18, are the four in which the English Version retains the JEHOVAH of the original. MAURER translates, "For JAH (the eternal unchangeable One, Exo 3:14) is JEHOVAH, the rock of ages" (compare Isa 45:17; Deu 32:15; Sa1 2:2).