Akademik

под лежачий камень вода не течет
ПОД ЛЕЖАЧИЙ <ЛЕЖАЧ> КАМЕНЬ (И) ВОДА НЕ ТЕЧЕТ{{}}
[saying]
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if a person makes no effort, he will make no progress, get nowhere (said when s.o. is inactive and does nothing toward attaining some goal, furthering some matter etc):
- - nothing ventured, nothing gained;
- no work, no money;
- no bees, no honey;
- no song, no supper;
- the sleeping fox catches no chickens.

Большой русско-английский фразеологический словарь. — М.: ACT-ПРЕСС КНИГА. . 2004.