From Longman Dictionary of Contemporary Englishfirst things firstfirst things firstFIRSTused to say that something should be done or dealt with first because it is the most important → first
Examples from the Corpus
first things first• Okay people, first things first: does everybody have their safety helmets?• Anyway, not to worry, first things first.• He declared that, in this situation, it was a case of first things first. 