Follow after love (diōkete tēn agapēn). As if a veritable chase. Paul comes back to the idea in 1Co 12:31 (same use of zēloute) and proves the superiority of prophecy to the other spiritual gifts not counting faith, hope, love of 1Co 13:13.
But rather that ye may prophesy (mallon de hina prophēteuēte). Distinct aim in view as in 1Co 14:5. Old verb from prophētēs, common in N.T. Present subjunctive, “that ye may keep on prophesying.”