It was narrated that Anas said:
"I went out with the Messenger of Allah (ﷺ) from Al-Madinah to Mekkah, and he continued to shorten his prayers, and he stayed there for ten days."
Reference: Sunan an-Nasa'i 1438
In-book reference: Book 15, Hadith 6
English translation: Vol. 2, Book 15, Hadith 1439