When must a man refrain from his wife if he stipulates divorce on Laylat al-Qadr (the Night of Power)?

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If a man tells his wife, 'You are divorced on Laylat al-Qadr,' he must seclude himself from her during the last ten nights of Ramadan. The basis for this is the Prophet's command to seek Laylat al-Qadr during these ten nights. This injunction to avoid her is an act of precaution (ihtiyat), as Laylat al-Qadr might fall on the first night of that period. However, the condition for the divorce to actually occur is not fulfilled until the very last night of the month, as it remains possible that the night falls then.