Narada Muni holds vīṇā in his hand. Vīṇā means stringed instrument, which is also carried by Sarasvatī, the goddess of learning. In India, even today, students worship mother Sarasvatī for material knowledge. The word Sarasvatī means knowledge. Even devotees worship Sarasvatī – Narada Muni, for spiriual knowledge. There are acharyas in the name of Sarasvatī – Bhakti Siddhanta Sarasvati. So there are two kinds of knowledge, avidyā and vidyā. Real vidyā or knowledge means brahma-vidyā – to inquire on Absolute Truth. Avidyā or knowledge in ignorance is taught in modern education, which promotes people to simply work hard for sense gratification. Because unless one puts hard labor they cannot be happy in this material world. Therefore one should take shelter of real knowledge.
Ref >> Srila Prabhupada Vani.