Musannaf Ibn Abi Shaybah 8914 — Laylat al-Qadr and which night it is

Sayyiduna Abdullah (bin Mas'ud) (may Allah be pleased with him) said: Whoever stands (in prayer) at night throughout the whole year will find Laylat al-Qadr.
Sayyiduna Ubayy (bin Ka'b) (may Allah be pleased with him) said: Abdullah knew that Laylat al-Qadr is the 27th night of Ramadan.