The rare Hebrew noun hamasas refers to dry, withered material — tinder or kindling that is easily consumed by fire. It appears in Isaiah 64:2 in the context of God's awesome theophanic fire that causes mountains to melt. The word captures extreme dryness and combustibility.
Hamasas (dry kindling) appears in one of Scripture's most powerful prayers for divine intervention (Isaiah 63:15–64:12). Isaiah pleads for God to come down as he did at Sinai — making mountains melt like hamasas before fire. The image is of utter helplessness before divine power. Theologically, it teaches that without God, all human strength and resistance is as dry tinder — instantly consumed in the presence of the Holy One.