"If he rise again and walk abroad" (Exodus 21:19). I might hear that this means within the house; therefore Scripture says "abroad." If "abroad," I might hear it even if he is wasting away; therefore Scripture says "if he rise again and walk abroad upon his staff" [meaning] in his full strength. This is one of three matters that Rabbi Yishmael would expound in the Torah as a kind of figure of speech. Similarly, "if the sun has risen upon him" (Exodus 22:2): does the sun rise upon him alone? Does it not rise upon the whole world? Rather, just as the sun means peace in the world, so too here: if it is known that the intruder departed from him in peace [with no intent to kill] and yet the householder killed him, he is liable. Similarly, "and they shall spread out the garment" (Deuteronomy 22:17): they clarify the matters as clear as a garment.
If He Rises and Walks and the Sun as a Sign
Yalkut Shimoni on Torah 331:5
(שמות כא יט) אִם יָקוּם וְהִתְהַלֵּךְ בַּחוּץ, שׁוֹמֵעַ אֲנִי בְּתוֹךְ הַבַּיִת, תַּלְמוּד לוֹמַר בַּחוּץ. אִי בַּחוּץ, שׁוֹמֵעַ אֲנִי אֲפִלּוּ מְתְנַוְּונָה, תַּלְמוּד לוֹמַר אִם יָקוּם וְהִתְהַלֵּךְ בַּחוּץ עַל מִשְׁעַנְתּוֹ, עַל בֻּרְיוֹ. זֶה אֶחָד מִשְּׁלֹשָׁה דְּבָרִים שֶׁהָיָה רַבִּי יִשְׁמָעֵאל דּוֹרֵשׁ בַּתּוֹרָה כְּמִין מָשָׁל. כַּיּוֹצֵא בּוֹ (שמות כב, ב) "אִם זָרְחָה הַשֶּׁמֶשׁ", וְכִי חַמָּה זוֹרַחַת עָלָיו בִּלְבַד, וַהֲלֹא עַל כָּל הָעוֹלָם כֻּלּוֹ זוֹרַחַת, אֶלָּא מַה שֶׁמֶשׁ שָׁלוֹם בָּעוֹלָם, אַף זֶה, אִם יוֹדֵעַ שֶׁבְּשָׁלוֹם הָלַךְ הֵימֶנּוּ וַהֲרָגוֹ, הֲרֵי זֶה חַיָּב. כַּיּוֹצֵא בּוֹ "וּפָרְשׂוּ הַשִּׂמְלָה", מְחַוְּרִין אֶת הַדְּבָרִים כְּשִׂמְלָה.