The answer is: A seraphim

Isaiah 6:6-7 - A seraphim, one of the heavenly beings in Isaiah's vision, touched Isaiah’s lips with a burning coal from the altar, symbolizing the purification of his sins and his readiness to deliver God’s message.

In Isaiah 6, we dive into a fascinating divine encounter that reveals much about spiritual cleansing and readiness for service. The seraphim are these incredible six-winged beings mentioned just a couple of times in the Bible, portraying an atmosphere of heavenly majesty. Their name even hints at burning or fiery characters, emphasizing their close association with God's holiness and purifying fire. That helps explain why a burning coal from the altar represented both purification and preparation.

This scene gives us a glimpse into God's incredible mercy. Imagine Isaiah trembling in response to God’s holy presence, aware of his imperfections amidst such splendor. The seraphim's action transforms what’s typically dangerous—the fire of God—into an instrument of cleansing. Fire, often a symbol of trial or judgment in the scripture, here depicts renewal, showing us that purification sometimes involves fiery trials.

Interestingly, Isaiah's vision parallels another significant burning moment in Scripture—Moses and the burning bush (Exodus 3). In both stories, the flame serves as a manifestation of God, drawing His people nearer in both challenge and grace.

It's also thought-provoking to realize how Isaiah’s purified lips would eventually proclaim complex and challenging prophecies and poetry, merging the earthly with the divine, ultimately preparing a message that would echo through generations—and echo forth the value of listening intent to divine calling. This central theme resonates through the entire canon. It suggests we, too, are called, equipped—if we’re just willing to let go and embrace our own journey in the fire toward growth and service!