"If you're thirsty, you may drink.”
They were the first words [Jill Pole] had heard since Scrubb had spoken to her on the edge of the cliff. For a second she stared here and there, wondering who had spoken.
Then the voice said again, “If you are thirsty, come and drink,” and of course she remembered what Scrubb had said about animals talking in that other world, and realized that it was the lion speaking. Anyway, she had seen its lips move this time, and the voice was not like a man's. It was deeper, wilder, and stronger; a sort of heavy, golden voice. It did not make her any less frightened than she had been before, but it made her frightened in rather a different way.
“Are you not thirsty?” said the Lion.
“I'm dying of thirst,” said Jill.
“Then drink,” said the Lion.
“May I - could I - would you mind going away while I do?” said Jill.
The Lion answered this only by a look and a very low growl. And as Jill gazed at its motionless bulk, she realized that she might as well have asked the whole mountain to move aside for her convenience.
The delicious rippling noise of the stream was driving her nearly frantic.
“Will you promise not to - do anything to me, if I do come?” said Jill.
“I make no promise,” said the Lion.
Jill was so thirsty now that, without noticing it, she had come step nearer.
“Do you eat girls?” she said.
“I have swallowed up girls and boys, women and men, kings and emperors, cities and realms,” said the Lion. It didn't say this as if it were boasting, nor as if it were sorry, nor as if it were angry. It just said it.
"I daren't come and drink," said Jill.
"Then you will die of thirst," said the Lion.
"Oh dear!" said Jill, coming another step nearer. "I suppose I must go and look for another stream then."
"There is no other stream," said the Lion.
(C. S. Lewis, The Silver Chair, chapter 2)
[The phrase "do not dare not to dare" comes from a similar scene in The Horse and His Boy, chapter 14:]
Then Hwin, though shaking all over, gave a strange little neigh, and trotted across to the Lion.
“Please,” she said, “you're so beautiful. You may eat me if you like. I'd sooner be eaten by you than fed by anyone else.”
“Dearest daughter,” said Aslan, planting a lion's kiss on her twitching, velvet nose, “I knew you would not be long in coming to me. Joy shall be yours.”
“Now, Bree,” he said, “you poor, proud frightened Horse, draw near. Nearer still, my son. Do not dare not to dare. Touch me. Smell me. Here are my paws, here is my tail, these are my whiskers. I am a true Beast.”
“Aslan,” said Bree in a shaken voice, “I'm afraid I must be rather a fool.”
“Happy the Horse who knows that while he is still young. Or the Human either…”