The levels of knowledge

Sufyan Az Zawri (Rahimahu Allah) said:

" The first (level) of  knowledge is (watch) silence. The secon is to listen carefully and memorize, the third is to act according to it. The fourth is to disseminate and teach."

SOURCE:  (Lammad Durral-Manzur minal-Qawlil-Ma-Zur nº 173)