2 Timothy 2:4-6

No soldier in active service gets entangled in the [ordinary business] affairs of civilian life; [he avoids them] so that he may please the one who enlisted him to serve. And if anyone competes as an athlete [in competitive games], he is not crowned [with the wreath of victory] unless he competes according to the rules. The hard-working farmer [who labors to produce crops] ought to be the first to receive his share of the crops.