וְיֹתֵ֥ר מֵהֵ֖מָּה בְּנִ֣י הִזָּהֵ֑ר עֲשׂ֨וֹת סְפָרִ֤ים הַרְבֵּה֙ אֵ֣ין קֵ֔ץ וְלַ֥הַג הַרְבֵּ֖ה יְגִעַ֥ת בָּשָֽׂר

A further word: Against them, my son, be warned! The making of many books is without limit And much study is a wearying of the flesh. 

Ecclesiastes 12:12