夏花已是旧时光里的沙粒
[xià huā yĭ shì jiù shí guāng lĭ de shā lì]
Summer flowers have become grains of sand in old times. By comparing summer flowers (symbolizing lively youth or love) to sands of past time, this sentence conveys memories and reminiscence for fleeting good old times with bittersweet nostalgia.