So, we've seen ash lining Jacob's cabin, but it wasn't fully explained why. Then, in LA X Parts 1 and 2, Bram uses almost identical ash to protect him from the Monster. It should be understood that both instances of the ash were to keep the Monster at bay. I'd like to posit a theory as to the origins of the ash. It has only been mentioned once about a volcano on the Island. Could it be that the ash from the volcano is the same ash used to protect Jacob's cabin, Bram, or the Temple? Is this volcano attached or near the Temple, so as those in Temple have access to it? An abundance of ash would be needed to be able to protect the Island, Jacob's cabin, or for Bram to have some. Perhaps he stole some from the broken ash line at Jacob's cabin, but where do those at the Temple replenish their source when they need more? Just as the pool of water in the Temple is sacred, perhaps the ash of the volcano is sacred in a way that acts as a barrier.