וַיִּפֹּ֧ל אַבְרָהָ֛ם עַל־פָּנָ֖יו וַיִּצְחָ֑ק וַיֹּ֣אמֶר בְּלִבּ֗וֹ הַלְּבֶ֤ן מֵאָֽה־שָׁנָה֙ יִוָּלֵ֔ד וְאִ֨ם־שָׂרָ֔ה הֲבַת־תִּשְׁעִ֥ים שָׁנָ֖ה תֵּלֵֽד׃
Then Abraham fell upon his face, and laughed, and said in his heart: ‘Shall a child be born unto him that is a hundred years old? and shall Sarah, that is ninety years old, bear?’
Targum Jonathan on Genesis
And Abraham fell on his face, and wondered, and said in his heart, Shall the son of a hundred years have progeny, and Sarah, the daughter of ninety years, bear a child?