There went in two and two unto Noah into the ark
 Of themselves, as Jarchi and Aben Ezra, being impressed with an instinct from God so to do; or by the ministry of angels, as observed (See Gill on Genesis 6:20) there were two of a sort, and some think four: the male and the female;
 and of some seven, or seven pairs, as before observed: as God commanded Noah;
 which respects his own and his family's entrance and the creatures; both were commanded by God, and attended to by Noah, who was obedient in all things. 
The Brenton translation of the Septuagint is in the public domain.