"Beneficial knowledge is that which expands the breast with its rays,
and by it the veils of the heart are lifted."

Beneficial knowledge is the knowledge of Allāh, His attributes, His names, and the knowledge by which one knows how to submit to Him and act properly in regards to His favors. This is the knowledge whose rays pervade the breast... lifting from the heart its veils and dispelling all doubts and misgivings.

Beneficial Knowledge
Shaykh Ibn `Abbād al-Rundī