Parashas Bo · Shemos 12:1 · TT note 2
Chabad.org — English translation + Rashi
Torah Temimah on Shemos 12:1, note 2 (on בְּאֶרֶץ מִצְרָיִם) points to Mechilta.
Sefaria — Exodus 12:1
Sefaria — Torah Temimah on Exodus 12:1
Sefaria — Mechilta
English: “In the land of Egypt” — outside the city. And why did He not speak with him inside the city? Because it was full of abominations and idols.
Derash on the extra wording בְּאֶרֶץ מִצְרָיִם: the dibbur took place outside the idolatrous city.
Divine speech to Moshe in Egypt was outside the city, which was filled with idols.