Sunan an-Nasa'i 456
سنن النسائي#456SahihIt 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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 5:9