Jami` at-Tirmidhi 2548

Salim bin 'Abdullah narrated from his father that the Messenger of Allah (s.a.w) said:"The breadth of the gate through which my Ummah shall enter Paradise is the distance that a good rider covers in three. (meaning three nights or three years and, and that [the latter] is more obvious) Despite that, they shall be constrained by it until their shoulders are almost crushed completely