"The sacredness of the divine names must be recognized by the professional scribe who writes the Scriptures, or the chapters for the phylacteries and the mezuzah. Before transcribing any of the divine names he prepares mentally to sanctify them. Once he begins a name he does not stop until it is finished, and he must not be interrupted while writing it, even to greet a king. If an error is made in writing it, it may not be erased, but a line must be drawn round it to show that it is canceled, and the whole page must be put in a genizah and a new page begun."