A man came to the Prophet ﷺ and said, "Prophet of Allah ﷺ, I am an old man, frail, and standing in prayer is hard for me. Tell me of a particular night, perhaps Allah will grant me Laylat al-Qadr on it."He replied, "Hold to the seventh."
أن رجلا أتى النبي ﷺ فقال: يا نبي الله ﷺ، إني شيخ كبير عليل يشق علي القيام، فأمرني بليلة لعل الله يوفقني فيها ليلة القدر. قال: عليك بالسابعة.
Ahmad narrated it (2149) from Muaz bin Hisham, my father told me, from Qatada, from Ikrima, from Abdullah bin Abbas, and he related it. Tabarani also narrated it through this same route in al-Kabir (11/311), as did Bayhaqi (4/313). Its chain of transmission is sahih. Haythami said in al-Majma (3/176), "Ahmad narrated it, and its narrators are the narrators of the Sahih," but he did not attribute it to Tabarani, even though Tabarani narrated it through the route of Ahmad.As for his statement, "Hold to the seventh," it means after seven nights have passed following the twenty-seventh. This statement should be understood as meaning that Laylat al-Qadr falling on the twenty-seventh is more likely in that particular year, not that it is always so. This is in order to reconcile the various hadiths reported on this subject, so that the sahih hadiths concerning the identification of Laylat al-Qadr do not appear to contradict one another.