Hadith 21:2
Waki’ narrated to us, from Usama bin Zayd, from Muhammad bin al-Munkadir, from Jabir, who said: I heard the Messenger of Allah (may Allah bless him and grant him peace) saying: "Ask Allah for beneficial knowledge, and seek refuge in Allah from knowledge that does not benefit."
حدثنا وكيع عن أسامة بن زيد عن محمد بن المنكدر عن جابر قال سمعت رسول الله صلى الله عليه وسلم يقول سلوا الله علما نافعا وتعوذوا بالله من علم لا ينفع