Negative commandment · Lo Ta’aseh #43 of 613
Not to shave the temples of our heads, as do the worshipers of false gods
שלא להקיף פיאת ראש ככומרי עבודה זרה
The verse · Vayikra 19:27
לֹא תַקִּפוּ פְּאַת רֹאשְׁכֶם וְלֹא תַשְׁחִית אֵת פְּאַת זְקָנֶךָ
“You shall not round the corners of your heads, neither shalt thou mar the corners of thy beard.”
The Rambam’s words
Not to shave the temples of our heads, as do the worshipers of false gods, as [Leviticus 19:27] states: "Do not shave your temples."
שלא להקיף פיאת ראש ככומרי עבודה זרה, שנאמר "ולא תקיפו, פאת ראשכם" (ראה ויקרא יט,כז).
Why · Sefer HaChinuch #251
To not encircle the corner of the head
“It is from the roots of the commandment [that it is] in order to distance from ourselves any matter of idolatry and anything that is done for its sake, and to make it forgotten from between our eyes and from all of our actions.”
Who & when
“And [it] is practiced in every place and at all times by males.”
Where in the Mishneh Torah
Hilchot Foreign Worship and Customs of the Nations הלכות עבודה זרה וחוקות הגויים