הִתְהַלֵּךְ לְפָנַי וֶהְיֵה תָמִים. זֶה שֶׁאָמַר הַכָּתוּב: הָאֵל תָּמִים דַּרְכּוֹ (תהלים יח, לא). מַהוּ תָּמִים? שֶׁחִבֵּב אֶת הַמִּילָה. אָמַר רַבִּי יִשְׁמָעֵאל, גְּדוֹלָה מִצְוַת מִילָה שֶׁשְּׁלֹשׁ עֶשְׂרֵה בְרִיתוֹת נִכְרְתוּ עָלֶיהָ מִן הַפְּסוּקִין הַמְפֹרָשִׁין. Walk before Me, and be thou wholehearted (Gen. 17:1). Scripture states elsewhere in allusion to this verse: As for God, His way is whole (Ps. 18:31). What is the meaning of His way is whole? It signifies that the Holy One, blessed be He, cherished the precept of circumcision. R. Ishmael stated: The rite of circumcision is so important that thirteen covenants were issued because of it. They are stated explicitly in the verses (of this section of the Torah).
וְהָיָה יוֹשֵׁב אַבְרָהָם וְתָמֵהַּ הֵיאַךְ יִמּוֹל. כֵּיוָן שֶׁאָמַר לוֹ הַקָּדוֹשׁ בָּרוּךְ הוּא וְאֶתְּנָה בְרִיתִי בֵּינִי וּבֵינֶךָ, מַה כְּתִיב אַחֲרָיו? וַיִּפֹּל אַבְרָהָם עַל פָּנָיו. כֵּיוָן שֶׁנָּפַל עַל פָּנָיו, רָמַז הַקָּדוֹשׁ בָּרוּךְ הוּא לְאוֹתוֹ מָקוֹם וַעֲקָצוֹ עַקְרָב, וְנִמְצָא מָהוּל. מִנַּיִן? מִן מַה שֶּׁכָּתוּב, וַיְדַבֵּר אִתּוֹ אֱלֹהִים לֵאמֹר אֲנִי הִנֵּה בְרִיתִי אִתָּךְ, הֲרֵי אַתָּה מָהוּל. וּכְתִיב: בְּעֶצֶם הַיּוֹם הַזּה נִמּוֹל אַבְרָהָם. מָל לֹא נֶאֱמַר אֶלָּא נִמּוֹל. Abraham sat and wondered where he was to be circumcised, after the Holy One, blessed be Him, informed him: I will establish My covenant between Me and thee (Gen. 17:2). What follows this verse? And Abraham fell on his face (ibid., v. 3). Once he fell on his face, the Holy One, blessed be He, indicated that place, and a scorpion bit him there. Forthwith, Abraham found himself circumcised. Whence do we know this? We know it from the verse And God spoke unto him, saying: As for Me, behold, My covenant is with thee (ibid., vv. 3–4); that is, behold, thou art circumcised. Furthermore, it is written: In the self-same day was Abraham circumcised (ibid., v. 26). Scripture does not say “he circumcised himself” but he was circumcised.
מָשָׁל לְמָה הַדָּבָר דּוֹמֶה? לְאוֹהֵב שֶׁל מֶלֶךְ שֶׁהָיָה רוֹצֶה לְשַׁדֵּךְ בִּתּוֹ שֶׁל מֶלֶךְ, וְהָיָה מִתְבַּיֵּשׁ וְלֹא הָיָה יוֹדֵעַ הֵיאַךְ יוּכַל לְסַפֵּר, אִם לְסַפֵּר בִּלְשׁוֹנוֹ, אִם עַל יְדֵי אַחֵר. הֵבִין הַמֶּלֶךְ מַה בְּלִבּוֹ. אָמַר לוֹ: יָדַעְתִּי מָה אַתָּה רוֹצֶה, הֲרֵי בִּתִּי לְתוֹךְ בֵּיתֶךָ. כָּךְ אַבְרָהָם, כְּשֶׁאָמַר לוֹ הַקָּדוֹשׁ בָּרוּךְ הוּא, וְאֶתְּנָה בְרִיתִי בֵּינִי וּבֵינֶךָ, נִתְבַּיֵּשׁ וְנָפַל עַל פָּנָיו, בִּנְפִילָתוֹ נִמְצָא שֶׁהוּא מָהוּל. אָמַר לוֹ: הִנֵּה בְרִיתִי אִתָּךְ. הֲדָא הוּא דִכְתִיב, אִמְרַת ה' צְרוּפָה (תהלים יח, לא), שֶׁצָּרַף אֶת זַרְעוֹ בִּבְרִית מִילָה, לְפִיכָךְ מָגֵן הוּא לְיִשְׂרָאֵל שֶׁהֵן חוֹסִין בּוֹ. וְלָמָּה What may this episode be compared to? It may be compared to a situation wherein a king’s friend is eager to marry the king’s daughter. Because he is extremely bashful, he does not know how to declare his love for her, whether to do so himself or through another. The king realized what was in the young man’s heart and so he said to him: “I know what you desire; my daughter is already in your house.” Abraham was likewise bewildered when the Holy One, blessed be He, said to him: I will make My covenant between Me and thee, and so he fell upon his face. While he was prostrate, he discovered that he was already circumcised. Forthwith, the Holy One, blessed be He, said: My covenant is made between Me and thee. Scripture says elsewhere in reference to the preceding verse: The word of the Lord is tried (Ps. 18:31). This implies that He tested Abraham’s offspring by bestowing upon them the precept of circumcision. Therefore, He is a shield unto all them that take refuge in Him (ibid.), to Israel who trust in Him.
לֹא נִמּוֹל אֶלָּא לְבֶן תִּשְׁעִים וָתֵשַׁע שָׁנָה, לְלַמֵּד לַגֵּרִים שֶׁאִם בִּקֵּשׁ אָדָם לְהִתְגַּיֵּר, לֹא יְהֵא אוֹמֵר זָקֵן אֲנִי וְהֵיאַךְ אֲנִי מִתְגַּיֵּר, יִלְמֹד מֵאַבְרָהָם שֶׁמָּל בֶּן תִּשְׁעִים וָתֵשַׁע שָׁנָה, לְכָךְ לֹא מָל אֶלָּא בֶּן תִּשְׁעִים וָתֵשַׁע שָׁנָה. Why was Abraham not circumcised until his ninety-ninth year? To teach us that a man who desires to be converted must not say: “I am old, how can I become a convert?” Let him learn from Abraham, who was circumcised in his ninety-ninth year. That is why Abraham was not circumcised until he attained that age.