“Is any matter beyond the Lord? At the time, I will return to you; at this time next year, Sarah will have a son” (Genesis 18:14). “Is any matter beyond the Lord?” Rabbi Yudan ben Rabbi Simon said: This is analogous to one who had two chains in his hand. He went to the blacksmith and said to him: ‘Can you repair them for me?’ He said to him: ‘I can make them in the first place, should I not be able to repair them?’ So, here, [God said:] ‘I am able to create them in the first place, should I not be able to restore them to the days of their youth?’