Wiktionary
first come, first served
a. (alternative spelling of first-come-first-served English) prov. (context idiomatic English) People will be dealt with in the order they arrive.
Wikipedia
First Come, First Served
First Come, First Served is the third studio album by American emcee and Ultramagnetic MCs member Kool Keith, who released the album under the alias Dr. Dooom. The album released on May 4, 1999