The third Mandala of the Rigveda has 62 hymns, mainly to Agni and Indra. It is one of the "family books" (mandalas 2-7), the oldest core of the Rigveda. Most hymns in this book are attributed to viśvāmitra gāthinaḥ
The verse 3.62.10 gained great importance in Hinduism as the Gayatri Mantra.
RV 3.53.14 refers to the Kīkaṭas, a non-Aryan tribe which most scholars have placed in Bihar (Magadha).
The dedication as given by Griffith is in square brackets
3.1 (235) [ Agni.] sómasya mā tavásaṃ vákṣi agne
3.2 (236) [Agni.] vaiśvānarâya dhiṣáṇām ṛtāvŕdhe
3.3 (237) [Agni.] vaiśvānarâya pṛthupâjase vípo
3.4 (238) [ Apris.] samít-samit sumánā bodhi asmé
3.5 (239) [Agni.] práti agnír uṣásaś cékitāno
3.6 (240) [Agni.] prá kāravo mananâ vacyámānā
3.7 (241) [Agni.] prá yá ārúḥ śitipṛṣṭhásya dhāsér
3.8 (242) [Sacrificial Post.] añjánti tvâm adhvaré devayánto