May
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
in the construction of public statutes, is to be construed "must" in all cases where the legislature mean to impose a positive and absolute duty, and not merely to give a discretionary power.
Minor v. Mechanics' Bank, 1 Pet 46, 64, 7 L. Ed. 47; New York v. Furze, 3 Hill (N. Y.) 612, 615.