未雨绸缪 --------- lay up against a rainy day

例句：
A: I’ve spent quite a little money on clothes.
我花了不少钱买衣服。
B: I know yon are well-off, but you’d better lay up against a rainy day.
我知道你生活富裕，但你最好能未雨绸缪。

同义词：
prepare for foul in fiair weather
prepare for a rainy day