par. 10—1—7.) Section 10—1—18 provides against the removal of a classified officer or employee who is appointed under the rules and after examination “except for cause upon written charges and after an opportunity to be heard in his own defense.” Ill. Rev. Stat. 1975, ch. 24, par. 10-1-18.
We consider that the commission has the authority to regard an employee’s moving his residence from the city of Harvey as “cause” for discharge. In Kammann v. City of Chicago (1906), 222 Ill. 63, 65-66, this court in construing a predecessor to section 10—1-18, stated: “The statute is silent as to what constitutes ‘cause.’ Manifestly the right to determine that question is left with the civil service commission . Joyce v. City of Chicago, 216 Ill. 466.” The position that the determination of “cause” is for the commission has been repeatedly recognized. (Klafter v. State Board of Examiners (1913), 259 Ill. 15, 21; Fantozzi v. Board of Fire & Police Commissioners (1963), 27 Ill. 2d 357, 360; Senese v. Civil Service Com. (1967), 88 Ill. App. 2d 172, 175; Sudduth v. Board of Fire & Police Commissioners (1964), 48 Ill. App. 2d 194, 213; Bruno v. Civil Service Com. (1962), 38 Ill. App. 2d 100, 108-09; Drury v. Hurley (1949), 339 Ill. App. 33, 39, 41.) Of course, the commission must act in a manner not arbitrary or unreasonable in determining what constitutes “cause.” Fantozzi v. Board of Fire & Police Commissioners (1963), 27 Ill. 2d 357, 360; Sudduth v. Board of Fire & Police Commissioners (1964), 48 Ill. App. 2d 194, *213; Bruno v. Civil Service Com. (1962), 38 Ill. App. 2d 100, *109; Drury v. Hurley (1949), 339 Ill. App. 33, 42. See Kreiser v. Police Board* (1977), 69 Ill. 2d 27, 30-31.
The legislature has made it clear that residence, as well as age, health, habits and moral character, may be an employment qualification of applicants for civil service employment. We cannot say that the commission, in promulgating its rule that “Removal from the City of