Makhdum Zayn ud Deen Chishti (Allah have mercy on him) said,

The likeness of one who turns away from practical knowledge and busies himself with disputation and rare branches of knowledge is like a sick man with a myriad of illnesses, at the point of death, who finds an intelligent physican; but rather than asking him about the cure for his illness he questions him about the properties of drugs and remedies, and the rare points of medicine.

The Guidance for the Intelligent