Abu Huraira reported Allah's Messenger (ﷺ) as saying

Prophet Ibrahim ﷺ never told a lie but only thrice: two times for the sake of Allah (for example, his words): "I am sick," and his words: "But it was the big one amongst them which has done that" and because of Sara (his wife). He had come in a land inhabited by haughty and cruel men along with Sara. She was very good-looking amongst the people, so he said to her: If these people were to know that you are my wife they would snatch you away from me, so if they ask you tell them that you are my sister and in fact you are my sister in Islam, and I do not know of any other Muslim in this land besides I and you. And when they entered that land the tyrants came to see her and said to him (the king): 'There comes to your land a woman, whom you alone deserve to possess', so he (the king) sent someone (towards her) and she was brought to him, and Ibrahim ﷺ stood in prayer. When she visited him (the tyrant king came) he could help but stretch his hand towards her and his hand was tied up. He said: 'Supplicate to Allah so that He may release my hand and I will do no harm to you.' She did that and the man repeated (the same highhandedness) and his hand was again tied up more tightly than on the first occasion. He said the same thing to her again, and she again did that (supplicated), but he repeated (the same highhandedness and his hands were tied up more tightly than on the previous occasion). He then again said: 'Supplicate your Lord so that He may set my hand free; by Allah I shall do no harm to you.' She did and his hand was freed. Then he called the person who had brought her and said to him: 'You have brought to me the satan and you have not brought to me a human being, so turn them out from my land,' and he gave Hajar as a gift to her. She returned (along with Hajar) and when Ibrahim ﷺ saw her, he said: 'How have you returned?' She said: 'With full safety (have I returned). Allah held the hand of that debauch and he gave me a maid-servant.' Abu Huraira said: 'O sons of the rain of the sky, she is your mother.'