Gaebelein, in his autobiography "Half a Century: The Autobiography of a Servant" pgs. 87-88, wrote this concerning Studies in Zechariah... "The first book I published was Studies in Zechariah. It has gone through nearly twenty editions, and has been published in a German translation in Germany. As this exposition contains so much about Christ, His first and His Second coming, I sent a free copy to every Jewish Rabbi in New York and vicinity, but I never heard a word from any of them. One day I noticed a young Hebrew in my Temple Court Bible Reading. He paid splendid attention and became a regular attendant. I spoke to him, and he said that he was the Secretary of Rabbi.... 'One day,' this young man said, ' the Rabbi received a book in the mai. He read it for a while and then fired it into the waste paper basket. I took it home with me. This book opened my eyes, and I believe Jesus is our Messiah and Saviour.' The book was Studies in Zechariah."