Fairy Tails from Many Lands — Katharine Pyle

THERE was once a king who had three sons, and he had also a golden apple tree, that bore nothing but golden apples, and this tree he loved as though it had been his daughter. The king was never able, however, to have any of the fruit it bore, for no sooner were the apples ripe than they would disappear in the night, and this in spite of a guard being set around the garden to watch it and see that no one entered in. One time the eldest prince came to the king and asked to be allowed to keep watch over the tree that night. “And if I do,” said he, “I promise you that nothing shall be allowed to approach it, not even the smallest sparrow.”