、。
When you study, study; when you play, play.
Literal
Study while [topic-は] study-and, play while [topic-は] play-(imperative).
An aphoristic imperative. ~間 sets up the temporal scope; the plain imperative 遊べ (from 遊ぶ) is rough and declarative, characteristic of proverbial exhortations. The parallel structure ('study during study-time, play during play-time') is a classic Japanese wisdom trope about focus and mindfulness.