1 Now the LORD appeared to him by the oaks of Mamre, while he was sitting at the tent door in the heat of the day. 2 When he lifted up his eyes and looked, behold, three men were standing opposite him; and when he sawthem, he ran from the tent door to meet them and bowed himself to the earth, 3 and said, “My Lord, if now I have found favor in Your sight, please do not pass Your servant by. 4 “Please let a little water be brought and wash your feet, and rest yourselves under the tree; 5 and I will bring a piece of bread, that you may refresh yourselves; after that you may go on, since you have visited your servant.” And they said, “So do, as you have said.” 6 So Abraham hurried into the tent to Sarah, and said, “Quickly, prepare three measures of fine flour, knead it and make bread cakes.” 7 Abraham also ran to the herd, and took a tender and choice calf and gave it to the servant, and he hurried to prepare it. 8 He took curds and milk and the calf which he had prepared, and placed it before them; and he was standing by them under the tree as they ate.
9 Then they said to him, “Where is Sarah your wife?” And he said, “There, in the tent.” 10 He said, “I will surely return to you at this time next year; and behold, Sarah your wife will have a son.” And Sarah was listening at the tent door, which was behind him. 11 Now Abraham and Sarah were old, advanced in age; Sarah was past childbearing. 12 Sarah laughed to herself, saying, “After I have become old, shall I have pleasure, my lord being old also?” 13 And the LORD said to Abraham, “Why did Sarah laugh, saying, `Shall I indeed bear a child, when I am so old?’ 14 “Is anything too difficult for the LORD? At the appointed time I will return to you, at this time next year, and Sarah will have a son.” 15 Sarah denied it however, saying, “I did not laugh”; for she was afraid. And He said, “No, but you did laugh.”
I skipped over this part pretty quickly the first time through, but here’s the most important line in this whole passage: “Is anything too difficult for the Lord?” It’s not a real question, it’s a rhetorical one. Of course, nothing is too difficult for the Lord. Abraham and Sarah had seen their share of miracles, but they were getting old, and holding onto God’s promise was getting harder every day. By this point, Sarah had resigned herself to having no children. The mere thought of bearing a child at her age prompted laughter, as it would for most of us. But God didn’t want them to forget the promise, He wanted to reassure them that anything was possible with Him.