Śrīmad-Bhāgavatam · Text 10.37.13
Who is speaking and story frame
स त्वं भूधरभूतानां दैत्यप्रमथरक्षसाम् ।
अवतीर्णो विनाशाय साधुनां रक्षणाय च ॥ १३ ॥
sa tvaṁ bhūdhara-bhūtānāṁ
daitya-pramatha-rakṣasām
avatīrṇo vināśāya
sādhunāṁ rakṣaṇāya ca
You, that very same creator, have now descended to the earth to annihilate the Daitya, Pramatha and Rākṣasa demons who are posing as kings, and also to protect the godly.
Read this verse on Vedabase.ioThis verse has no purport; its meaning is explained by the verses around it.
From Canto 10, chapter 14 onward, the translation and purports were completed by Śrīla Prabhupāda's disciples after his departure, and published by the Bhaktivedanta Book Trust.