Zirr b. Habaish reported: I thu asked Ubayy b. Ka'b (Allah be pleased with him): Your brother (in faith) Ibn Mas'ud says: He who stands (for the night prayer) throughout the year would find Lailat-ul-Qadr, whereupon he said: May Allah have mercy upon him;
(he said these words) with the intention that people might not rely only (on one night), whereas he knew that it (Lailat-ul-Qadr) is in the month of Ramadan and it is the twenty-seventh night. He then took oath (without making any exception, i. e. without saying Innsha Allah) that it was the twenty-seventh night. I said to him: Abu Mundhir, on what ground do you say that? Thereupon he said: By the indication or by the sign which the Messenger of Allah ﷺ gave us, and that is that on that day (the sun) would rise without having any ray in it.

وَحَدَّثَنَا مُحَمَّدُ بْنُ حَاتِمٍ، وَابْنُ أَبِي عُمَرَ، كِلاَهُمَا عَنِ ابْنِ عُيَيْنَةَ، - قَالَ ابْنُ حَاتِمٍ حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، - عَنْ عَبْدَةَ، وَعَاصِمِ بْنِ أَبِي النَّجُودِ، سَمِعَا زِرَّ بْنَ حُبَيْشٍ، يَقُولُ سَأَلْتُ أُبَىَّ بْنَ كَعْبٍ - رضى الله عنه - فَقُلْتُ إِنَّ أَخَاكَ ابْنَ مَسْعُودٍ يَقُولُ مَنْ يَقُمِ الْحَوْلَ يُصِبْ لَيْلَةَ الْقَدْرِ . فَقَالَ رَحِمَهُ اللَّهُ أَرَادَ أَنْ لاَ يَتَّكِلَ النَّاسُ أَمَا إِنَّهُ قَدْ عَلِمَ أَنَّهَا فِي رَمَضَانَ وَأَنَّهَا فِي الْعَشْرِ الأَوَاخِرِ وَأَنَّهَا لَيْلَةُ سَبْعٍ وَعِشْرِينَ . ثُمَّ حَلَفَ لاَ يَسْتَثْنِي أَنَّهَا لَيْلَةُ سَبْعٍ وَعِشْرِينَ فَقُلْتُ بِأَىِّ شَىْءٍ تَقُولُ ذَلِكَ يَا أَبَا الْمُنْذِرِ قَالَ بِالْعَلاَمَةِ أَوْ بِالآيَةِ الَّتِي أَخْبَرَنَا رَسُولُ اللَّهِ ﷺ أَنَّهَا تَطْلُعُ يَوْمَئِذٍ لاَ شُعَاعَ لَهَا .