na tyajyam karyam eva tat
yajno danam tapas caiva
yajna—sacrifice; dana—charity; tapah—penance; karma—activities; na—never; tyajyam—to be given up; karyam—must be done; eva—certainly; tat—that; yajnah—sacrifice; danam—charity; tapah—penance; ca—also; eva—certainly; pavanani—purifying; manisinam—even of the great souls.
Acts of sacrifice, charity and penance are not to be given up but should be performed. Indeed, sacrifice, charity and penance purify even the great souls.
The yogis should perform acts for the advancement of human society. There are many purificatory processes for advancing a human being to spiritual life. The marriage ceremony, for example, is considered to be one of these sacrifices. It is called vivaha-yajna. Should a sannyasi, who is in the renounced order of life and who has given up his family relations, encourage the marriage ceremony? The Lord says here that any sacrifice which is meant for human welfare should never be given up. Vivaha-yajna, the marriage ceremony, is meant to regulate the human mind to become peaceful for spiritual advancement. For most men, this vivaha-yajna should be encouraged even by persons in the renounced order of life. Sannyasis should never associate with women, but that does not mean that one who is in the lower stages of life, a young man, should not accept a wife in the marriage ceremony. All prescribed sacrifices are meant for achieving the Supreme Lord. Therefore, in the lower stages, they should not be given up. Similarly, charity is for the purification of the heart. If charity is given to suitable persons, as described previously, it leads one to advanced spiritual life.
Link to this page: http://prabhupadabooks.com/bg/18/5