They went in two and two unto Noah into the ark, the male and the female, as God had commanded Noah.

-Bible (Old Testament)
Genesis 7:9.

Two are better than one; because they have a good reward for their labour. For if they fall, the one will lift up his fellow: but woe to him that is alone when he falleth; for he hath not another to help him up.

-Bible (Old Testament)
Ecclesiastes 4:9^10.

And if one prevail against him, two shall withstand him; and a threefold cord is not quickly broken.

-Bible (Old Testament)
Ecclesiastes 4:12.

   Can two walk together, except they be agreed?

-Bible (Old Testament)
Amos 3:3.

If ever two were one, then surely we.

-Bradstreet, Anne ne¤  e Dudley
  Several Poems Compiled with Great Variety of  Wit and Learning,'To My Dear and Loving Husband'.

Tea for two, and two for tea. 183

-Caesar, Irving
  No! No! Nanette,'Tea for Two' (with Otto Harbach. Music by VincentYoumans). Roman  general  and  statesman.  As  consul  (59  BC)  and  pro- consul   (58^50   BC)   he  extended  Roman  power   in  Gaul  and Britain.  Refusing  to  disband  his  army,  he  came  into  conflict with the Senate, supported by Pompey, whom Caesar defeated in  the  civil war  that  followed.  He  became  dictator  for  life,  but was  assassinated in  44  BC.  His  works  include  the Commentarii ('War  Commentaries'),  De  Bello  Gallico  ('On  the  Gallic War', 7 vols) and De Bello Civili ('On the CivilWar', 3 vols).

I must have two you knowöto come and go.One to come, and one to go.

-Dodgson
  The King speaking of his messengers. Through the Looking-Glass, ch.7,'The Lion and the Unicorn'.

   The formula 'Two and two is five' is not without its attractions.

-Dostoevsky, Fyodor Mikhailovich
  Notes from Underground.

This will be the issue of that darling Plea, of being one and not two; it will be turned upon the Scots with a Vengeance; and their 45 Scots Members may dance round to all Eternity, in thisTrap of their own making.

-Fletcher (of Saltoun), Andrew
  State of the Controversy betwixt United and Separate Parliaments, a critique of the proposed Union.

To think that two and two are four And neither five nor three The heart of man has long been sore And long 'tis like to be.

-Housman, A(lfred) E(dward)
  Last Poems, no.35.

   For the sin ye do by two and two ye must pay for one by one!

-Kipling, (Joseph) Rudyard
  'Tomlinson'.

   Freedom is the freedom to say that two plus two make four. If that isgranted, all else follows.

-Orwell, George pseudonym of  Eric Arthur Blair
  Nineteen Eighty-Four, pt.1, ch.7.

   What two ideas are more inseparable than Beer and Britannia.

-Smith, Rev Sydney
  In the Edinburgh Review, quoted in H Pearson The Smith of Smiths (1934), ch.11.

   There are two kinds of Arctic problems, the imaginary and the real.Of the two, the imaginary are the most real.

-Stefansson,Vilhjalmur
  TheArctic in Fact and Fable.

Two things are always the same the dance and war.

-Stein, Gertrude
  Everybody's Autobiography, ch.5.