"You shall not afflict any widow or orphan" (Exodus 22:21). From this I know only of a widow and an orphan; from where do I learn that the same applies to every other person? Scripture teaches, "You shall not afflict." These are the words of Rabbi Yishmael. Rabbi Akiva says: "Any widow or orphan," those whose way it is to be afflicted [being weak and unprotected], it is of them that Scripture speaks. "If you afflict him at all" (Exodus 22:22) [the doubled verb teaches]: one who afflicts much and one who afflicts a little [are both included].
You Shall Not Afflict Any Widow or Orphan
Yalkut Shimoni on Torah 349:3
(שמות כב כא) כָּל אַלְמָנָה וְיָתוֹם לֹא תְעַנּוּן, אֵין לִי אֶלָּא אַלְמָנָה וְיָתוֹם, שְׁאַר כָּל אָדָם מִנַּיִן, תַּלְמוּד לוֹמַר לֹא תְעַנּוּן, דִּבְרֵי רַבִּי יִשְׁמָעֵאל. רַבִּי עֲקִיבָא אוֹמֵר, כָּל אַלְמָנָה וְיָתוֹם, שֶׁדַּרְכָּן לֵיעַנּוֹת, בָּהֶן דִּבֵּר הַכָּתוּב. (שמות כב כב) אִם עַנֵּה תְעַנֶּה אֹתוֹ, אֶחָד עִנּוּי מְרֻבֶּה וְאֶחָד עִנּוּי מֻעָט.