Sentence:  Agni is the one who is introduced by <WSD>Manu</WSD>, who is kindled by <WSD>Manu</WSD>; one requests him to rule at the present sacrifice, as he had done it for <WSD>Manu</WSD>, when he "offered the first oblation, with kindled fire, with his (attentive) heart and soul, along with the seven priests" to the gods (X, 63, 7). 
Meaning of the word marked with <WSD> tags:  A title accorded the progenitor of mankind, first king to rule this earth, who saves mankind from the universal flood.