Charles Spurgeon Commentary Isaiah 26:3-4

"Thou wilt keep [him] in perfect peace, [whose] mind [is] stayed [on thee]; because he trusteth in thee. Trust ye in Jehovah for ever; for in Jehovah, [even] Jehovah, is an everlasting rock." — Isaiah 26:3-4 (ASV)

Whose mind is stayed on you: because he trusts in you.

Trust you in the LORD for ever: for in the LORD JEHOVAH is everlasting strength:

Nothing can be too hard for him, for he has "everlasting strength." Nothing can ever happen in the future to overthrow him, for his is not decaying strength, but "everlasting strength."

Hold on to that strength, you children of God. You may even suck honey out of this "Rock of Ages" (see margin), for there is indescribable sweetness in it: Trust you in the LORD for ever:—not only sometimes, but always;—"for ever," because there is strength in God for ever.