Ecclasiastes 4:9-12

Two are better than one: they get a good wage for their labor.
If the one falls, the other will lift up his companion.
Woe to the solitary man!
For if he should fall, he has no one to lift him up.
So also, if two sleep together, they keep each other warm.
How can one alone keep warm?
Where a lone man may be overcome, two together can resist.
A three-ply cord is not easily broken.