It is narrated from Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) that when a quarter of the night had passed, the Messenger of Allah (peace and blessings be upon him) would (wake and) say: "O people, remember Allah! O people, remember Allah! (The first blast of the Trumpet,) al-Rajifah, has come, to be followed by (the second blast,) al-Radifah. Death has come with all its horrors, death has come with all its horrors." So Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) said: O Messenger of Allah, I send abundant blessings upon you; so how much of my supplication should I devote to you (for sending blessings)? He (peace and blessings be upon him) said: "As much as you wish." This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.