إِنَّ مِنَ الْعِلْمِ جَهْلًا
Translation: Some knowledge can amount to ignorance.
Source: أبو داود
The purpose of learning is sound understanding, good action, and self-improvement. A person may accumulate information but misuse it for arrogance, needless arguments, or neglect of essential responsibilities. In that case the knowledge fails to benefit its possessor.
مِنَ الْعِلْمِ means “some kinds of knowledge” and جَهْلًا means ignorance. As in the preceding sentence, the expression does not condemn all learning. It warns that information pursued or applied wrongly can resemble ignorance in its results.
Beneficial knowledge involves accurate learning, humility, appropriate priorities, and acting on what is learned.