Jami` at-Tirmidhi 3351

Zirr bin Hubaish [and Zirr bin Hubaish’s Kunyah is Abu Mariam] said:“I said to Ubayy bin Ka’b: ‘Your brother Abdullah bin Mas’ud says: “Whoever stands (in voluntary prayer) the whole year, then he will have reached the Night of Al-Qadr.’” So he said: ‘May Allah forgive Abu Abdur-Rahman. He knows that is during the last ten (nights) of Ramadan, and that it is the night of the twenty-seventh. But he wanted the people to not rely upon that.’ Then he uttered an oath, that without exception it is on the night of the twenty-seventh.” He said: “I said to him: ‘Why is it that you say that O Abu Al-Mindhir?’ He said: “By the sign or indication which the Messenger of Allah informed us of: ‘That the sun rises on that day having no beams with it.’”