Book 4: Prayer (Kitab Al-Salat): Detailed Rules of Law about the Prayer during JourneyDa'if Munkar, and the Sahih version is 19 days as in a previous hadith.
Chapter 430
When Should The Traveler Stop Shortening The Prayer
باب مَتَى يُتِمُّ الْمُسَافِرُ
Da'if Munkar, and the Sahih version is 19 days as in a previous hadith.