(3) باب كَيْفَ فُرِضَتِ الصَّلاَةُ .
It was narrated that Ibn 'Abbas said:
"The Salah was enjoined on the lips of the Prophet (ﷺ), four Rak'ahs while resident, and two while traveling, and one Rak'ah during times of fear." (RU)
Reference (RU): Sunan an-Nasa'i 456 (RU)
In-book reference (RU): Book 5, Hadith 9 (RU)
English translation (RU): Vol. 1, Book 5, Hadith 457 (RU)