What is the detailed evidence for the permissibility of combining the intention of religion and worldliness in the pursuit of knowledge?

A Muslim is permitted to have two intentions when seeking religious knowledge: the intention of drawing closer to Allah and benefiting Muslims, and the intention of obtaining a certificate for employment and salary. There is no sin upon him in this. However, if his intention is confined solely to worldly matters, he is in grave danger and falls under the severe warning mentioned in the Hadith: "Whoever learns knowledge by which the Face of Allah Almighty is sought, but does not learn it except to obtain a worldly عرضًا ( عرضًا: a worldly gain or عرضًا ( عرضًا: a worldly gain or benefit) thereby, will not find the fragrance of Paradise on the Day of Resurrection." This does not diminish his reward in the slightest, because the pure Sharia came with both religious and worldly incentives.