The Hebrew verb kahah means to grow dim, faint, or be weakened. It is used of failing eyesight, dimming fire, or the fading of strength. It carries the sense of something once bright or strong that is now declining.
Kahah is used in Isaiah 42:3 in the famous Servant Song: 'A bruised reed he will not break, and a smoldering (dim) wick he will not snuff out.' God does not extinguish what is faint — He tends and restores. The word provides contrast to the sustaining power of the Spirit, pointing to divine gentleness with human weakness.