Rishi: Yājñavalkya-tradition (Śukla-Yajurvedic school attribution; individual mantra-r̥ṣi not explicitly marked here).
Devata: Pavitra as deified purifier; by bandhu Dyāvāpṛthivī and Mātariśvan (Vāyu/Agni-carrier).
Chandas: Mixed/prose-yajus (Yajus-formula; not a fixed ṛgvedic metre).
Samhita Patha (Devanagari)वसो॑ः प॒वित्र॑मसि॒ द्यौ॑रसि पृथि॒व्य॒सि मात॒रिश्व॑नो घ॒र्मो॒ऽसि वि॒श्वधा॑ असि । पर॒मेण॒ धाम्ना॒ दृᳪह॑स्व॒ मा ह्वा॒र्मा ते॑ य॒ज्ञप॑तिर्ह्वार्षीत् ॥
Transliterationvásoḥ pavítram asi dyáur asi pṛthivī́ asi mātáriśvano gharmó ’si viśvádhā asi | paraméṇa dhā́mnā dṛ́ṃhasva mā́ hvā́r mā́ te yajñápatir hvārṣīt ||
Translationতুমি বসুগণের পবিত্র (শোধক); তুমি দ্যৌ (স্বর্গ); তুমি পৃথিবী; তুমি মাতরিশ্বনের ঘর্ম (উষ্ণ তেজ); তুমি সর্বব্যাপী। পরম ধাম (সর্বোচ্চ অবস্থান) দ্বারা তুমি দৃঢ় হও; অমঙ্গলকে ডেকো না; যজ্ঞপতি (যজ্ঞের অধিপতি) যেন তোমার বিরুদ্ধে (কোনো অমঙ্গল) আহ্বান না করেন।
Padapatha (Word Analysis)वसोः । पवित्रम् । असि । द्यौः । असि । पृथिवी । असि । मातरिश्वनः । घर्मः । असि । विश्वधा । असि । परमेण । धाम्ना । दृंहस्व । मा । ह्वाः । मा । ते । यज्ञपतिः । ह्वार्षीत् ।
Word by Wordवसोःof the Vasu (wealth/‘Vasu’ deity) पवित्रम्purifier; strainer मातरिश्वनःof Mātariśvan (Vāyu/Agni-carrier) घर्मःGharma (heated offering; hot drink/oblation) विश्वधाin every way; universally धाम्नाby (your) abode/splendour दृंहस्वmake (us/it) firm; strengthen यज्ञपतिःthe lord/master of the sacrifice ह्वार्षीत्has harmed/has gone wrong (towards) 
Entities MentionedP
Pavitra (deified purifier)D
Dyāvā-Pṛthivī (Heaven and Earth)Y
Yajñapati (Lord of the sacrifice) Viniyoga (Ritual Application)