The number "two" has two different meanings in the Bible. In most cases "two" indicates a joining together or unification. This is easy to see if we consider the conflicts we tend to have between our "hearts" and our "heads" -- between what we want and what we know. Our "hearts" tell us that we want pie with ice cream for dinner; our "heads" tell us we should have grilled chicken and salad. If we can bring those two together and actually want what's good for us, we'll be pretty happy. We're built that way -- with our emotions balanced against our intellect -- because the Lord is built that way. His essence is love itself, or Divine Love, the source of all caring, emotion and energy. It is expressed as Divine Wisdom, which gives form to that love and puts it to work, and is the source of all knowledge and reasoning. In His case the two aspects are always in conjunction, always in harmony. It's easy also to see how that duality is reflected throughout creation: plants and animals, food and drink, silver and gold. Most importantly, it's reflected in the two genders, with women representing love and men representing wisdom. That's the underlying reason why conjunction in marriage is such a holy thing. So when "two" is used in the Bible to indicate some sort of pairing or unity, it means a joining together. In rare cases, however, "two" is used more purely as a number. In these cases it stands for a profane or unholy state that comes before a holy one. This is because "three" represents a state of holiness and completion (Jesus, for instance, rose from the tomb on the third day), and "two" represents the state just before it.

883. 'The dove returned to him at evening time' means that these started to show themselves a little; and 'evening time' is similar to pre-morning twilight. This in like manner becomes clear from that has been stated already at verse 8, and also from the fact that here it is called 'evening time'. Concerning 'evening', see what has been stated in Genesis 1, where six times the statement is made 'there was evening and there was morning'. 'Evening' is a word that has to do with regeneration and indeed with that state when a person is still in near-darkness, or when there is still only a tiny quantity of light showing itself to him. Morning itself is described in verse 13 below by 'he removed the roof from the ark and saw out'. Because 'evening' meant the pre-morning twilight, mention of the evening is made so many times in the Jewish Church. This also is why sabbaths and festivals began from evening onwards, and why Aaron was commanded to light the sacred lamp 'in the evening', Exodus 27:21.