In plain words
The poet says: Before you come to the end, your sores packed with risen pus, flies' eggs settling on them and foul matter oozing everywhere, tormented by the itching of flies until you lose your senses: if you say with your mouth Namō nārāyaṇāya, join your hands above your head, and so go [to Paramapadam], then afterwards, even if [the nityasūris and the freed] stood surety, they would never let you go back to this world.