The Protection of Tikkun Chatzos:

Sefer Bnei Shileishim explains that "Kiryas Chatzos" is a hint to the concept of "Tikkun Chatzos.” The pasuk is saying that Bilaam and his curses cannot harm those who recite Tikkun Chatzos. He further states that the words “efes kitzeihu tireh" (you will only see part of them) is a hint to the mitzvah of tzitzis (which are placed on the “katzeh' – corner – of a garment). Thus, the Torah is saying that tzitzis are a protection from sin (as is stated in Menachos 44A).