וַיִּפֹּ֧ל אַבְרָהָ֛ם עַל־פָּנָ֖יו וַיִּצְחָ֑ק וַיֹּ֣אמֶר בְּלִבּ֗וֹ הַלְּבֶ֤ן מֵאָֽה־שָׁנָה֙ יִוָּלֵ֔ד וְאִ֨ם־שָׂרָ֔ה הֲבַת־תִּשְׁעִ֥ים שָׁנָ֖ה תֵּלֵֽד׃
Lalu Abraham sujud dengan wajahnya ke tanah dan tertawa gembira, dan ia berkata dalam hatinya: “Akankah seorang yang berumur seratus tahun mendapat anak? Dan Sara, yang berumur sembilan puluh tahun, akankah ia melahirkan?”
The Midrash of Philo
Why did Abraham fall on his face and laugh? (Genesis 17:17).
Allegorical Interpretation of Genesis
[85] Some even before their birth God endows with a goodly form and equipment, and has determined that they shall have a most excellent portion. Dost thou not see what He says concerning Isaac to Abraham when unable to trust that he shall ever become the father of such an offspring, nay when he actually laughed at the promise and said, “Shall it come to pass to him that is a hundred years old, and shall Sarah who is ninety years old bear a child?” (Gen. 17:17). He ratifies and confirms it saying, “Yes, Sarah thy wife shall bear thee a son and thou shalt call his name Isaac, and I will establish My covenant with Him for an everlasting covenant” (ibid. 19).
On the Change of Names
[154] These promises might well have puffed up the mind to soar into the heights. But to convict us, so often proud-necked at the smallest cause, he falls down and straightway laughs (Gen. 17:17) with the laughter of the soul, mournfulness in his face, but smiles in his mind, where joy vast and unalloyed has made its lodging.