Ecclesiastes 12:11-13

The sayings of the wise are like goads, and like nails firmly fixed are the collected sayings that are given by one shepherd. Of anything beyond these, my child, beware. Of making many books there is no end, and much study is a weariness of the flesh. The end of the matter; all has been heard. Fear God, and keep his commandments; for that is the whole duty of everyone.