"Then the LORD appeared to him by the terebinth trees of Mamre, as he was sitting in the tent door in the heat of the day. So he lifted his eyes and looked, and behold, three men were standing by him; and when he saw them, he ran from the tent door to meet them, and bowed himself to the ground, and said, 'My Lord, if I have now found favor in Your sight, do not pass on by Your servant. Please let a little water be brought, and wash your feet, and rest yourselves under the tree. And I will bring a morsel of bread, that you may refresh your hearts. After that you may pass by, inasmuch as you have come to your servant.' They said, 'Do as you have said'" (Gen. 18:1-5).
Abraham has been blessed to have several opportunities to dialogue with God. He will get yet another such opportunity here, though he does not know it at first. As Abraham was resting during the hottest part of the day, he observed three men nearby. Although most today would pay little attention to strangers passing by their homes, Abraham was different. He didn't just wave or say hello, he ran (as a 99-year-old man!) to meet them. He didn't extend his hand to shake theirs but bowed down (not as a form of worship but out of respect and courtesy; e.g., Gen. 23:7,12; I Sam. 24:8). Abraham requests that these strangers not pass him by without enjoying some hospitality. He wants them to rest in the shade and he will prepare food for them. They are willing to do so.
"So Abraham hurried into the tent to Sarah and said, 'Quickly, make ready three measures of fine meal; knead it and make cakes.' And Abraham ran to the herd, took a tender and good calf, gave it to a young man, and he hastened to prepare it. So he took butter and milk and the calf which he had prepared, and set it before them; and he stood by them under the tree as they ate" (Gen. 18:6-8). Abraham hurries to prepare meat and bread. He enlists the help of Sarah and one of his servants. He also brings out butter and milk. Had Abraham known who his visitors were, it seems unlikely that he would have offered physical food. Abraham treats these strangers as he would any other guests, like royalty! He is very polite and serves them the best. He personally oversees the process. What a fine example! Friends, are you hospitable like this great man of faith? Excuses are easy to make for not behaving like Abraham, but we are commanded to be hospitable (cf. Rom. 12:13).
"Then they said to him, 'Where is Sarah your wife?' So he said, 'Here, in the tent.' And He said, 'I will certainly return to you according to the time of life, and behold, Sarah your wife shall have a son.' (Sarah was listening in the tent door which was behind him.) Now Abraham and Sarah were old, well advanced in age; and Sarah had passed the age of child-bearing. Therefore Sarah laughed within herself, saying, 'After I have grown old, shall I have pleasure, my lord being old also?' And the LORD said to Abraham, 'Why did Sarah laugh, saying, "Shall I surely bear a child, since I am old?" Is anything too hard for the LORD? At the appointed time I will return to you, according to the time of life, and Sarah shall have a son.' But Sarah denied it, saying, 'I did not laugh,' for she was afraid. And He said, 'No, but you did laugh!'" (Gen. 18:9-15).
Abraham stands nearby while the men eat. The men ask about Abraham's wife, and then one of them made a declaration about Sarah having a baby. This was not a new message (cf. Gen. 17:16), but here we see how Sarah received the message--with disbelief! She had been listening in on the conversation between the men. She mocked the message silently to herself. She knew (or at least thought she knew) that she wouldn't be having any children at age 90! But she was wrong! Genesis 18:13 finally explicitly reveals the identity of one of the visitors to the readers--it is the LORD (along with a couple angels; cf. Heb. 13:2)! They had taken a human form to visit and speak with Abraham. God, who certainly knew Sarah's heart (as well as ours!), rebukes her for her unbelief, and she lies out of fear. "Is anything too hard for the LORD?" Now that is a question we should ponder! Almighty God is still in control and He does as He pleases! Enabling a 90-year-old woman to give birth to a son is not a challenge at all for the God who made the Universe! Abraham knew this, and Sarah would learn soon enough. This rebuke from God apparently was sufficient to convince her for she would soon conceive Isaac "by faith" (Heb. 11:11).