Where did the king spend the night?

In Tolstoy's story "Three Questions," the King spends the night "on the threshold" of the Hermit's hut. That exact location is significant because the King is still, at this point, in the middle of his process of self-discovery and learning. He sleeps half within the Hermit's realm, which is a realm of goodness and knowledge, and half outside of it, so to speak, for he has not yet fully learned God's purpose for him on earth.
The King's intention has been to obtain answers to the "three questions" from the Hermit, but he's been sidetracked by the appearance of the wounded Bearded Man. He's exhausted because of having first helped the Hermit in the task of digging in the ground, and then having washed and bandaged the Bearded Man's wound. It is only after the "brief summer night" is over that the King is awakened. At first, he feels disoriented, and he is then told by the Hermit that his (the King's) own life was saved by the tasks of charity he undertook, first in aiding the Hermit's labor and then in aiding the Bearded Man. The Bearded Man had the intention of killing the King in order to avenge his brother's death, and would in fact have killed him had the King not stopped to aid the Hermit's work. The moral of Tolstoy's parable, then, is explained at the close—we have been sent into the world for the purpose of doing good alone.