“When, after leaving my enemy’s house, I arrived at the place for which I was bound,” replied Isaac, “I was in sore sickness and pain; but I found there a doctor of great skill, who gave me a powerful antidote, and after much suffering I rose from my sick-bed healed. And from the Christian doctor I also received knowledge of the only antidote for sin,—whether it be the open sin which man condemns, or the poison of sin, such as covetousness, lying concealed in the heart.”