Bhashya
प्रजापतिः लोकानभ्यतपत् लोकानुद्दिश्य तत्र सारजिघृक्षया ध्यानलक्षणं तपश्चचार ।तेषां तप्यमानानां लोकानां रसान् साररूपान्प्रावृहत् उद्धृतवान् जग्राहेत्यर्थः ।कान् ? अग्निं रसं पृथिव्याः, वायुमन्तरिक्षात्, आदित्यं दिवः ॥
In plain words
Prajāpati focused upon the worlds. Wishing to extract their innermost core, he engaged in deep meditative austerity. As those worlds felt the heat of his concentration, he drew forth their vital essences. What were they? Agni as the essence of the earth, Vāyu of the atmosphere, and Āditya of the heavens.
Close to the Sanskrit
Prajāpati brooded upon the worlds—targeting the worlds with the desire to capture their essence there, he practiced austerity characterized by meditation. Of those worlds being heated, he extracted their essences, consisting of the vital core; he gathered them up, that is the meaning. Which ones? Agni as the essence of the earth, Vāyu of the atmosphere, Āditya of heaven.