Non-Beneficial Knowledge

One of the supplications of the Prophet of Islam was: “O God, save me from such knowledge as is not beneficial (Allahumma inni aauzu bika min ilmin la yanfa).” (Sahih Muslim, Hadith No. 2722)

Real knowledge is beneficial to humanity. On the other hand, the knowledge that is not beneficial to humanity is not a desired piece of knowledge. Making efforts to gain such knowledge is completely a waste of time.