The Wycliffe Handbook of Preaching & Preachers, W. Wiersbe, p. 205
D. L. Moody made an covenant with God that he would witness for Christ to at least one person each day. One night, about ten o'clock, he realized that he had not yet witnessed; so he went out in to the street and spoke to a man standing by a lamppost, asking him, "Are you a Christian?" The man flew into a violent rage and threatened to knock Moody into the gutter.
Later, that same man went to an elder in the church and complained that Moody was "doing more harm in Chicago than ten men were doing good." The elder begged Moody to temper his zeal with knowledge. Three months later, Moody was awakened at the YMCA by a man knocking at the door. It was the man he had witnessed to. "I want to talk to you about my soul," he said to Moody. He apologized for the way he had treated Moody and said that he had had no peace ever since that night on Lake Street when Moody witnessed to him. Moody led the man to Christ and he became a zealous worker in the Sunday school.