Last Ten Nights of Ramadan

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Hadith - Al-Tirmidhi #2102, Narrated Anas ibn Malik; Ubayy ibn Ka'b

The Prophet sallallahu alaihi wasallam was accustomed to engage in private devotion in the mosque during the last ten nights of Ramadan; but one year he sallallahu alaihi wasallam omitted it and he engaged in it for twenty nights the next year.

[Tirmidhi transmitted it, and AbuDawud and Ibn Majah transmitted it from Ubayy ibn Ka'b.]

Hadith - Al-Tirmidhi #2107, Narrated Abdullah ibn Umar [Ibn Majah transmitted it.]

When the Prophet sallallahu alaihi wasallam observed a period of private devotion in the mosque, his bedding was placed for him, or a couch was put down for him, behind the column of repentance.