(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." (ES)
Reference (ES): Sunan an-Nasa'i 456 (ES)
In-book reference (ES): Book 5, Hadith 9 (ES)
English translation (ES): Vol. 1, Book 5, Hadith 457 (ES)