Rashi citing Targum Yonasan: It is [Lechalek,] to divide (get his share of) his inheritance amidst the nation (the Kohanim). While the Bavliyim besieged [Yerushalayim], he did not leave it, for he was praying that the city not be captured.

Radak: Lachalik is like Lehachalik; the Hei is omitted, and the vowel (Patach) was moved [from under the Hei] to under the Lamed. The same applies to "Lashmid Ma'uzneha" (Yeshayah 23:11) and similar verses. Lehachalik is to separate himself from there, for he was amidst the Am, and he feared lest they incarcerate him, for he said "even if you would strike the entire army of Bavel