Sayyiduna Abdullah bin Unays (may Allah be pleased with him) relates: On the morning of the twenty-first of Ramadan I was sitting in the gathering of Banu Salimah, and I was the youngest of them. They said: Who will ask the Messenger of Allah (peace and blessings be upon him) for us when Laylat al-Qadr is? I said: I (will ask). So I went until I reached (the Messenger of Allah (peace and blessings be upon him)) at the time of Maghrib on the twenty-second night. I prayed with him (peace and blessings be upon him), then I waited for him at his door until he passed by me. He (peace and blessings be upon him) took me into his house, called for food for me and said: "Eat." I saw myself holding back from the food because of how little there was. Then he (peace and blessings be upon him) called for his sandals and stood up, and said: "It seems you have some need?" I said: Yes, some men of Banu Salimah have sent me to you; they ask when Laylat al-Qadr is. He (peace and blessings be upon him) said: "What date of the month is it today?" I said: The twenty-second. He (peace and blessings be upon him) said: "It is tonight." Then he came back and said: "Or else the coming night, or else the coming night."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13942