Living Seforim

Rav Ruderman used to show his talmidim a letter he had received in 5719 (1959) from the Steipler Gaon. The Steipler was asking for financial help to print the first volume of his major work, Kehillas Yaakov. In the letter he wrote that he had seen and learned Avodas HaLevi, which Rav Ruderman had written in his youth, and found in it wonderful chiddushim on the hardest parts of Seder Kodshim. He urged Rav Ruderman to write more seforim like it.

After showing the letter, Rav Ruderman would say, “I could write ten more volumes of Avodas HaLevi from the chiddushim I have, but now my seforim are leibidige seforim, living seforim, my talmidim.” He explained that teaching takes complete concentration. The Gemara says one should seek to learn Torah from a rebbe only if he resembles a malach, and a malach can carry out only one mission at a time. Teaching his talmidim took all of him, so he could not sit and write seforim.