With the publication of Luther's manuscripts of the Bible translations in the Weimar edition of his works, a veritable mine has been opened to the investigators of Luther's language. These manuscripts were written in the years 1523-1530; Zerbster Handschrift, 1523; Berliner Handschrift, 1523-1524; Heidelberger Handschrift, 1527-1528; Gothaer Handschrift, 1530; etc. Luther began intensive work upon his translation of the Old Testament immediately after the appearance of the revision of the New Testament, 1522. He had profited from a closer study of the earlier editions, of the sources, and of German life and language, before he entered upon his monumental work. He had also attained to a more philosophical view of life and had become more skilled in the art of translation.