'Alone' in the Bible

There is one who is alone, and he has neither son nor brother. There is no end to all of his labor, neither are his eyes satisfied with wealth. "For whom then, do I labor, and deprive my soul of enjoyment?" This also is vanity. Yes, it is a miserable business.

For if they fall, the one will lift up his fellow; but woe to him who is alone when he falls, and doesn't have another to lift him up.

Again, if two lie together, then they have warmth; but how can one keep warm alone?

If a man prevails against one who is alone, two shall withstand him; and a threefold cord is not quickly broken.