旧言就语不二情不言不语不失心
[jiù yán jiù yŭ bù èr qíng bù yán bù yŭ bù shī xīn]
An intricate phrase combining multiple ideas: honoring past commitments ('old words') with steadfast feelings ('one unchanging love') and silently caring without expressing it outwardly. Overall suggests a loyal but silent love.