Agnimile purohitam yajnasya devam rtvijam

hotaram ratnadhatamam

Original Mantra in Sanskrit –

अग्निमीळे पुरोहितं यज्ञस्य देवमृत्विजम् । होतारं रत्नधातमम् ॥

The meaning of the mantra –

Before the time of origin of the universe, self effulgent fire god holds the atom. The creator God created the macro universe over and over at the time of origin.

The hidden science within mantra : 

According to the first mantra of Rigveda, there is a self effulgent fire which is the eternal support of all. Self existed and the leader of all.