'Four' in the Bible

To the leech are two daughters, 'Give, give, Lo, three things are not satisfied, Four have not said 'Sufficiency;'

Three things have been too wonderful for me, Yea, four that I have not known:

For three things hath earth been troubled, And for four -- it is not able to bear:

Four are little ones of earth, And they are made wiser than the wise:

Three there are going well, Yea, four are good in going: