The title verse is explained as saying that if Michael, representing holiness, and Samael, representing defilement, strive and hurt the congregation of Yisrael, Samael will be punished by the Holy One, blessed be He.
371. Ra'aya Meheimna (the Faithful Shepherd). "If men strive..." (Shemot 21:22) These are Michael and Samael- MICHAEL REPRESENTS HOLINESS, SAMAEL, DEFILEMENT. "...And hurt a woman with child..." (Ibid.). This is the Congregation of Yisrael, DENOTING MALCHUT; "so that her children depart from her," refers to the exile; "he shall be surely punished," refers to Samael; "according as the woman's husband will lie upon him" refers to the Holy One, blessed be He.