SB 1.2.9
dharmasya hy apavargyasya
nartho ’rthayopakalpate
narthasya dharmaikantasya
kamo labhaya hi smrtah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
All occupational engagements are certainly meant for ultimate liberation. They should never be performed for material gain. Furthermore, according to sages, one who is engaged in the ultimate occupational service should never use material gain to cultivate sense gratification.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
We have already discussed that pure devotional service to the Lord is automatically followed by perfect knowledge and detachment from material existence. But there are others who consider that all kinds of different occupational engagements, including those of religion, are meant for material gain. The general tendency of any ordinary man in any part of the world is to gain some material profit in exchange for religious or any other occupational service. Even in the Vedic literatures, for all sorts of religious performances an allurement of material gain is offered, and most people are attracted by such allurements or blessings of religiosity. Why are such so-called men of religion allured by material gain? Because material gain can enable one to fulfill desires, which in turn satisfy sense gratification. This cycle of occupational engagements includes so-called religiosity followed by material gain and material gain followed by fulfillment of desires. Sense gratification is the general way for all sorts of fully occupied men. But in the statement of Suta Gosvami, as per the verdict of the Srimad-Bhagavatam, this is nullified by the present sloka.
One should not engage himself in any sort of occupational service for material gain only. Nor should material gain be utilized for sense gratification. How material gain should be utilized is described as follows.