Rishi: Not specified in the excerpt; within Vājasaneyin riddle-cycle tradition.
Devata: Enigmatic/cosmic forms (to be identified in the following mantra).
Chandas: Not securely determinable; prose-like riddle cadence.
Samhita Patha (Devanagari)का स्वि॑दासीत्पू॒र्वचि॑त्ति॒: किᳪ स्वि॑दासीद् बृ॒हद्वय॑: । का स्वि॑दासीत्पिलिप्पि॒ला का स्वि॑दासीत्पिशङ्गि॒ला
Transliterationkā́ svíd āsīt pūrvácittiḥ kíṃ svíd āsīd bṛhádvayaḥ | kā́ svíd āsīt pilippilā́ kā́ svíd āsīt piśaṅgilā́
TranslationWhat, indeed, was the first intelligence? What, indeed, was the great bird? What, indeed, was Pilippilā? What, indeed, was Piśaṅgilā?
Padapatha (Word Analysis)का । स्वित् । आसीत् । पूर्व-चित्तिः । किम् । स्वित् । आसीत् । बृहत्-वयः । का । स्वित् । आसीत् । पिलिप्पिला । का । स्वित् । आसीत् । पिशङ्गिला ।
Word by Wordस्वित्indeed? I wonder; perhaps (interrogative particle) पूर्वचित्तिःthe former thought/intent; prior conception बृहद्वयःgreat vigor/strength (lit. great ‘vayas’) पिलिप्पिलाPilipilā (a named being/creature; proper name) पिशङ्गिलाPiśaṅgilā (the tawny/reddish one; proper name) 
Viniyoga (Ritual Application)