Here are some of the excerpts from the Rig Vedas detailing the description of the God of fire:
"HYMN CXIV. Rudra. 1. To the strong Rudra bring we these our songs of praise, to him the Lord of Heroes with the braided hair, That it be well with all our cattle and our men, that in this village all be healthy and well-fed. 2 Be gracious unto us, O Rudra, bring us joy: thee, Lord of Heroes, thee with reverence will we serve. Whatever health and strength our father Manu won by sacrifice may we, under thy guidance, gain. 3 By worship of the Gods may we, O Bounteous One, O Rudra, gain thy grace, Ruler of valiant men. Come to our families, bringing them bliss: may we, whose heroes are uninjured, bring thee sacred gifts, 4 Hither we call for aid the wise, the wanderer, impetuous Rudra, perfecter of sacrifice. May he repel from us the anger of the Gods: verily we desire his favourable grace. 5 Him with the braided hair we call with reverence down, the wild-boar of the sky, the red, the dazzling shape. May he, his hand filled full of sovran medicines, grant us protection, shelter, and a home secure. 6 To him the Maruts’ Father is this hymn addressed, to strengthen Rudra's might, a song more sweet than sweet. Grant us, Immortal One, the food which mortals eat: be gracious unto me, my seed, my progeny. 7 O Rudra, harm not either great or small of us, harm not the growing boy, harm not the full-grown man. Slay not a sire among us, slay no mother here, and to our own dear bodies, Rudra, do not harm. 8 Harm us not, Rudra, in our seed and progeny, harm us not in the living, nor in cows or steeds, Slay not our heroes in the fury of thy wrath. Bringing oblations evermore we call to thee. 9 Even as a herdsman I have brought thee hymns of praise: O Father of the Maruts, give us happiness, Blessed is thy most favouring benevolence, so, verily, do we desire thy saving help. 10 Far be thy dart that killeth men or cattle: thy bliss be with us, O thou Lord of Heroes. Be gracious unto us, O God, and bless us, and then vouchsafe us doubly-strong protection. 11 We, seeking help, have spoken and adored him: may Rudra, girt by Maruts, hear our calling. This prayer of ours may Varuṇa grant, and Mitra, and Aditi and Sindhu, Earth and Heaven."
"HYMN XXXIII. Rudra: 1. FATHER of Maruts, let thy bliss approach us: exclude us not from looking on the sunlight. Gracious to our fleet courser be the Hero may we transplant us, Rudra, in our children. 2 With the most saving medicines which thou givest, Rudra, may I attain a hundred winters. Far from us banish enmity and hatred, and to all quarters maladies and trouble. 3 Chief of all born art thou in glory, Rudra, armed with the thunder, mightiest of the mighty. Transport us over trouble to well-being repel thou from us all assaults of mischief. 4 Let us not anger thee with worship, Rudra, ill praise, Strong God! or mingled invocation. Do thou with strengthening balms incite our heroes: I hear thee famed as best of all physicians. 5 May I with praise-songs win that Rudra's favour who is adored with gifts and invocations. Ne’er may the tawny God, fair-checked, and gracious, swifthearing, yield us to this evil purpose. 6 The Strong, begirt by Maruts, hath refreshed me, with most invigorating food, imploring. As he who finds a shade in fervent sunlight may I, uninjured, win the bliss of Rudra. 7 Where is that gracious hand of thine, O Rudra, the hand that giveth health and bringeth comfort, Remover of the woe that Gods have sent us? O Strong One, look thou on me with compassion. 8 To him the strong, great, tawny, fair-complexioned, I utter forth a mighty hymn of praises. We serve the brilliant God with adorations, we glorify, the splendid name of Rudra. 9 With firm limbs, multiform, the strong, the tawny adorns himself with bright gold decorations: The strength of Godhead ne’er departs from Rudra, him who is Sovran of this world, the mighty. 10 Worthy, thou carriest thy bow and arrows, worthy, thy manyhued and honoured necklace. Worthy, thou cuttest here each fiend to pieces: a mightier than thou there is not, Rudra. 11 Praise him the chariot-borne, the young, the famous, fierce, slaying like a dread beast of the forest. O Rudra, praised, be gracious to the singer. let thy hosts spare us and smite down another. 12 I bend to thee as thou approachest, Rudra, even as a boy before the sire who greets him. I praise thee Bounteous Giver, Lord of heroes: give medicines to us as thou art lauded. 13 Of your pure medicines, O potent Maruts, those that are wholesomest and health-bestowing, Those which our father Manu hath selected, I crave from. Rudra for our gain and welfare. 14 May Rudra's missile turn aside and spare us, the great wrath of the impetuous One avoid us. Turn, Bounteous God, thy strong bow from our princes, and be thou gracious to our seed and offspring. 15 O tawny Bull, thus showing forth thy nature, as neither to be wroth, O God, nor slay us. Here, Rudra, listen to our invocation. Loud may we speak, with heroes, in assembly."
"HYMN XV. Agni: 6 Worship ye Agni, Agni, with your log of wood; praise your beloved, your beloved guest with songs. Invite ye the Immortal hither with your hymns. A God among the Gods, he loveth what is choice, loveth our service, God mid Gods. 7 Agni inflamed with fuel in my song I sing, pure, Cleanser, steadlast, set in tront at sacrifice. Wise Jātavedas we implore with prayers for bliss the Priest, the holy Singer, bounteous, void of guile. 8 Men, Agni, in each age have made thee, Deathiess One, their envoy, offering-bearer, guard adorable. With reverence Gods and mortals have established thee, the ever-watchful, omnipresent Household Lord. 9 Thou, Agni, ordering the works and ways of both, as envoy of the Gods traversest both the worlds. When we lay claim to thy regard and gracious fare, be thou to us a thriceprotecting friendly guard. 10 Him fair of face, rapid, and fair to look on, him very wise may we who know not follow. Let him who knows all rules invite for worship, Agru announce our offering to the Immortals. 11 Him, Agni, thou deliverest and savest who brings him prayer to thee the Wise, O Hero, The end of sacrifice or its inception; yea, thou endowest him with power and riches."