Rishi: Atharvan (as paradigmatic first-kindler; mantra speaks in his name/precedent)
Devata: Agni
Chandas: Yajus-prose with triadic cola; not strictly metrical in performance
Samhita Patha (Devanagari)पु॒री॒ष्यो॒ऽसि वि॒श्वभ॑रा॒ अथ॑र्वा त्वा प्रथ॒मो निर॑मन्थदग्ने । त्वाम॑ग्ने॒ पुष्क॑रा॒दध्यथ॑र्वा॒ निर॑मन्थत । मू॒र्ध्नो विश्व॑स्य वा॒घत॑:
Transliterationpūrīṣyò ’si viśvá-bharā átharvā tvā prathamó nír amanthad agne | tvā́m agne púṣkarād ádhy átharvā nír amanthata | mū́rdhno víśvasya vā́ghataḥ
Translationতুমি বেদীৰ মাটিৰ (পুৰীষ্য) অগ্নি, সকলো বহনকাৰী। হে অগ্নি, অথৰ্বনেই প্ৰথমে তোমাক মন্থন কৰি উলিয়ালে। হে অগ্নি, পুষ্কৰাৰ পৰা, ওপৰৰ পৰা, অথৰ্বনেই তোমাক মন্থন কৰি উলিয়ালে—সমগ্ৰ যজমানৰ মূৰ্ধাৰ পৰা।
Padapatha (Word Analysis)पुरीष्यः । असि । विश्व-भरा । अथर्वा । त्वा । प्रथमः । निर्-अमन्थत् । अग्ने । त्वाम् । अग्ने । पुष्करात् । अधि । अथर्वा । निर्-अमन्थत । मूर्ध्नः । विश्वस्य । वाघतः ।
Word by Wordपुरीष्यः(O Agni,) rich in dung/fuel; having purīṣa (manure as fuel) विश्वभराall-bearing; supporter of all निरमन्थत्churned out; produced by churning पुष्करात्from the lotus / from (the place called) Puṣkara निरमन्थतchurned out; produced by churning मूर्ध्नःof the head; from the head (as source, in sense) विश्वस्यof the whole; of the universe वाघतःof the worshipper/offerer 
Viniyoga (Ritual Application)