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take care of yourself; get well soon
風邪を引いた友人に「お大事に」と言った。
I said 'take care' to my friend who caught a cold.
病院を出る患者に医者がお大事にと声をかけた。
The doctor told the patient leaving the hospital to take care.
体調が悪いと聞いてお大事にと伝えてください。
I heard you're not feeling well, please take care.