اَلْجَامِعَةِ 12:12

وَبَقِيَ، فَمِنْ هَذَا يَاٱبْنِي تَحَذَّرْ: لِعَمَلِ كُتُبٍ كَثِيرَةٍ لَا نِهَايَةَ، وَٱلدَّرْسُ ٱلْكَثِيرُ تَعَبٌ لِلْجَسَدِ.

And further, by these, my son, be admonished: of making many books there is no end; and much study is a weariness of the flesh.