While the historians were perfecting their histories certain prophets also were beginning to commit their sermons to writing. The oldest recorded address in the Old Testament is probably that of Amos at Bethel. His banishment from the northern kingdom under strict injunction not to prophesy there (Am. vii. 10-17) may well explain why he resorted to writing to give currency to his prophetic message, though, like Paul in later days, he undoubtedly regarded writing as an inferior substitute for the spoken word. Jeremiah appears to have preached twenty years before he dictated a line to his scribe Baruch, and then it was because he could not personally speak in the temple (xxxvi. 1-5). Sometimes complete sermons of the prophets are preserved, but more often we seem to have only extracts and epitomes. In some of the prophetic books, like that of Jeremiah, there are also popular reports of a prophetic address, and narrative sections, telling of the prophet's experience. [Sidenote: _The editing of the earlier prophecies_] Evidences of editing are very apparent in the earlier prophecies. Sudden interruptions, and verses or clauses, in which appear ideas and literary style very different from that of the immediate context, indicate that many of the prophecies have been supplemented by later notes, some explanatory and some hortatory. Other longer passages are intended to adjust the earlier teaching to later conditions and beliefs and so to adapt them to universal human needs that they are not limited to the hour and occasion of their first delivery. Some of these passages come from the hands of disciples of the prophets and often contain valuable additional data; others are from later prophetic editors and scribes. A detailed comparison, for example, of the Hebrew and Greek versions of Jeremiah quickly discloses wide variations of words, verses, and even long passages, added in one or the other text by later hands. All these additions testify to the deep interest felt by later generations in the earlier writings, even before they were assigned a final place in the canon. It is one of the important tasks of biblical scholars to distinguish the original from the additions and thus determine what were the teachings of each prophet and what are the contributions of later generations. [Sidenote: _The background of Isaiah xl.-lv._]