Who couldn't use a bit more strength to help get us through life's challenges? Notice how, in Isaiah 12:2 and 24:4, the prophet uses the name "LORD JEHOVAH" in association with finding strength in the LORD: "Behold, God is my salvation; I will trust, and not be afraid: for the LORD JEHOVAH is my strength and my song; he also is become my salvation." (Isaiah 12:2); "Trust ye in the LORD for ever: for in the LORD JEHOVAH is everlasting strength" (Isaiah 26:4) .
In both of these verses, the "LORD" preceding JEHOVAH is Jah in Hebrew, i.e. a shortened form of "JEHOVAH." So, the Hebrew reads "Jah Jehovah." Jehovah is God's personal name. This name is generally understood to mean "the existing one" or "the self-existing one." The name emphasize that God was not created; rather He is the self-existing Creator. He exists simply because He is; we exist because He created us.
In Biblical Hebrew, a word may be strengthened or emphasized by using similar forms of the same word in close proximity. For example, in Genesis 2:17, we read, "But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die." In the Hebrew, "surely die" is literally "dying thou shalt die" (muth tamuth). The LORD used two forms of the verb "to die" in order to emphasize and strengthen the idea that Adam and Eve would experience a spiritual death as the result of their sin. Similarly, in Isaiah, we may observe that God uses two forms of His name, Jah Jehovah, in order to strongly emphasizes the idea that He is the self-existing one.
It's interesting to note that the only verses in Scripture that use Jah Jehovah (Isaiah 12:2; 24:4) deal with our ability to trust the LORD because He is our source of strength. Jah Jehovah seems to be used there to emphasize that because the LORD is the only "self-existing one" (emphasized twice), he is the only true source of our strength. We may trust in the LORD and find strength in Him because He is the only one who is the source of His own existence.
Of course, we see the LORD as the source of our strength in other parts of the Old Testament, too. In Psalm 43:2, the psalmist states, "For thou art the God of my strength..." He then applies that truth by asking, "... why go I mourning because of the oppression of the enemy?" We may rejoice in the strengthening of the LORD!
We also find the promise of strengthening in the Lord in the New Testament. In Phillippians 4:13, Paul writes, "I can do all things through Christ which strengtheneth me."
Our Lord is the only true source of our strength. Let's call upon the LORD for the strength we need each day!