(Exodus 22:20) commands: "And a stranger you shall not afflict and you shall not oppress him." The Mekhilta identifies two distinct prohibitions within this verse. "You shall not afflict" refers to verbal mistreatment — taunting, insulting, or reminding the convert of his former life. "You shall not oppress" refers to financial mistreatment — cheating the convert in business dealings.
The verbal prohibition is illustrated with a vivid example. Do not say to a convert: "Yesterday you worshipped the deity of Nevo, and the flesh of swine is still between your teeth, and you would dare contend with me!" This taunt weaponizes the convert's past against him. It treats his former life as a permanent stain rather than a chapter that has been closed.
The Mekhilta then adds a warning: if you taunt the convert, he can taunt you right back. How? "For you were strangers in the land of Egypt." Every Israelite descends from people who were once outsiders in a foreign land. The convert's vulnerability mirrors Israel's own historical experience. Anyone who mocks a convert's foreign origins opens himself to the same critique — your ancestors were foreigners too.
This teaching grounds the convert's protection not in abstract ethics but in shared history. Israel knows what it feels like to be a stranger. That memory creates a permanent obligation to treat converts with dignity, because every Israelite's family was once exactly where the convert is now.