"And Judah sent the kid of the goats" (Genesis 38:20). "Playing in His inhabited world" (Proverbs 8:31) — the Torah, which plays before the creatures. The Holy One, blessed be He, said to Judah: You deceived your father with a kid of the goats; by your life, Tamar will deceive you with a kid of the goats. "And it came to pass about three months later" (Genesis 38:24). There we learned: a pregnant woman is considered such from the time her pregnancy becomes recognizable. And how much is the recognition of pregnancy? Sumchus says in the name of Rabbi Meir: three months. And although there is no proof of the matter, there is a remembrance of the matter: "And it came to pass about three months later." A remembrance of the matter? It is a great proof! Because there is one who gives birth at nine months and one who gives birth at seven.
Deceived by a Kid as the Torah Laughs at the World
Yalkut Shimoni on Torah 145:5
(בראשית לח כ) וַיִשְׁלַח יְהוּדָה אֶת גְּדִי הָעִזִּים. (משלי ח, לא) "מְשַׂחֶקֶת בֶּתֵבֵל אַרְצוֹ", הַתּוֹרָה שֶׁהִיא מְשַׂחֶקֶת עַל הַבְּרִיּוֹת אָמַר לוֹ הַקָּדוֹשׁ בָּרוּךְ הוּא לִיהוּדָה, אַתְּ מְרַמֶה לְאָבִיךָ בִּגְדִי עִזִּים, חַיֶּיךָ שֶׁתָּמָר מְרַמָּה לְךָ בִּגְדֵי עִזִּים. (בראשית לח כד) וַיְהִי כְּמִשְׁלשׁ חֳדָשִׁים. תַּמָּן תָּנִינָן, מְעֻבֶּרֶת דַּיָּה שַׁעְתָּהּ מִשֶּׁהֻכַּר עֻבָּרָהּ. וְכַמָּה הַכָּרַת הָעֻבָּר, סוּמְכוּס אוֹמֵר בְּשֵׁם רַבִּי מֵאִיר, שְׁלֹשָׁה חֳדָשִׁים. וְאַף עַל פִּי שֶׁאֵין רְאָיָה לַדָּבָר זֵכֶר לַדָּבָר, וַיְהִי כְּמִשְׁלֹשׁ חֳדָשִׁים. זֵכֶר לַדָּבָר, רְאָיָה גְּדוֹלָה הִיא, מִשּׁוּם דְּאִכָּא דְּיָלְדָה לְתִשְׁעָה וְאִכָּא דְּיָלְדָה לְשִׁבְעָה.