There is an old Japanese folktale known as Ubasuteyama. It is a sad story of poor village folk forced to take their parents up into the mountains and abandon them there in accordance with village regulations at a time of famine.
A son carrying his mother on his back trudged through hills and valleys until he was deep in the mountain, far away from all human habitation. At the moment of parting the mother asked her son if he thought he could return home safely without becoming lost.
“It’ll soon be dark,” she told him. “All the time you’ve been carrying me here, I have been catching twigs in my outstretched hands and dropping them one after another so that they could act as signposts on your way home. If you are not sure which way to go when you come to a crossing of the ways, choose the path on which you find a broken twig. Get home safely!” So saying she bid him farewell, bowing with her palms together. Left alone in the mountain, of course, the old mother had no means of returning home over fields and hills.
Even in such a difficult situation and faced with her own death, the mother looks after her son rather than herself. The mother hasn’t abandoned her son, even if he has abandoned her. What deep love that is! Such true parental feeling! This is none other than the love and compassion of the Buddha. There is a poem about it:
In the depths of the mountains,
Who was it for the aged mother snapped
One twig after another?
Heedless of herself
She did so
For the sake of her son
It is said that when he came to Japan Einstein was much moved by this story
「奥山に 枝折り々々は誰が為ぞ 親の身棄て 帰る子のため」