In plain words
The poet, to those who toil at other means: You who do not know the way that brings release, who torment your bodies [with fasting] until they are a bare frame of bones, who hold to that penance long and then eat, and so toil on: the true means that grants release, the supreme being whom the Vedas show, the sweet delight of the eternal ones [nityasūris], is Nārāyaṇa.