Rishi: Śukla Yajurveda ritual tradition (yajus-formula complex; specific ṛṣi attribution varies)
Devata: Tvaṣṭṛ (with divine viś as attendants/carriers)
Chandas: Yajus (prose-formula with mixed cadence)
Samhita Patha (Devanagari)उ॒पा॒वीर॒स्युप॑ दे॒वान्दैवी॒र्विश॒: प्रागु॑रु॒शिजो॒ वह्नि॑तमान् । देव॑ त्वष्ट॒र्वसु॑ रम ह॒व्या ते॑ स्वदन्ताम्
Transliterationupāvī́rasya úpa devā́n daivī́r víśaḥ prā́g uruśíjo váhnitamān | déva tvaṣṭar vásu rama havyā́ te svadantām
Translationإلى الآلهة، في المقدّمة، (تتقدّم) الشعوبُ الإلهيّةُ التابعةُ للحامي القريب—أولئك الواسعو الانتشار، خيرُ الحاملين. أيّها الإله تْفَشْتْر، أيّها الصالح، افرح؛ ولتكن قرابينُك حلوةً لك.
Padapatha (Word Analysis)उ॒पा॒-वीर॑स्य । उप॑ । दे॒वान् । दैवीः॑ । विशः॑ । प्राक् । उ॒रु॒शिजः॑ । वह्नि॑-तमान् । देव॑ । त्वष्टः॑ । वसु॑ । र॒म॒ । ह॒व्या । ते॒ । स्व॒द॒न्ताम्
Word by Wordअवीरस्यof the unheroic / of one without heroes प्राक्forward; in front; eastward उरुशिजःthe broad-conquering (Urushij) ones (a class of beings/attendants) वह्नितमान्the most bearing/most conveying (i.e., best carriers) त्वष्टःO Tvaṣṭṛ (the divine artisan) वसुO Vasu (good one/wealth-giver) स्वदन्ताम्let them be sweet/pleasing; let them taste well 
Entities MentionedA
Agni (implied as vahnitama, ‘best bearer’)D
Daivī Viś (divine ‘peoples’/hosts) Viniyoga (Ritual Application)