It is narrated from Hazrat Naeem bin Nahham (may Allah be pleased with him) that once, on a very cold night, the muezzin began the call to prayer. I was lying in my blanket, wishing that he would announce, "Pray in your tents." When he reached "Hayya 'ala al-falah," he made the announcement, "Pray in your tents." Later, I asked him about this, and he told me that the Prophet (peace and blessings be upon him) himself had instructed him to do so.