Charles Spurgeon Commentary Isaiah 26:4

"Trust ye in Jehovah for ever; for in Jehovah, [even] Jehovah, is an everlasting rock." — Isaiah 26:4 (ASV)

Trust ye in the LORD for ever:

Not sometimes, but always; not for a certain number of days during your season of trial, but if the trial should last a lifetime, trust ye in the Lord for ever.

For in the LORD JEHOVAH is everlasting strength:

If he could fail you, you would do well to be looking out for another shelter; but since his strength is everlasting, let your faith also be everlasting. Lives there a man who has fully trusted in God, and yet has been confounded? Is there one anywhere who has really relied upon the invisible power of Jehovah, and yet has found him to fail in the hour of need? It cannot, and it shall not be.