Back when there were just two humans (and after the Flood, eight), Jehovah commanded: “Be fruitful and become many. ”
بَعْدَ ذٰلِكَ ،‏ يَتَّخِذَانِ قَرَارَهُمَا بِحَيْثُ يُحَافِظَانِ عَلَى ضَمِيرٍ طَاهِرٍ أَمَامَ ٱللهِ .‏