Very few of us hear the call of God because we are not in the place to answer; the call does not communicate because we have not the nature of the One Who is calling. In the case of Isaiah, his soul was so attuned because of the tremendous crisis he had passed through, that the call of God was recorded to his amazed soul. God did not lay a strong compulsion on Isaiah; Isaiah was in the presence of God and he overheard, as it were, the soliloquy of God: “Whom shall I send, and who will go for Us?”