Sunan Abi Dawud 2407
سنن أبي داود#2407SahihNarrated Jabir b. 'Abd Allah :The Prophet (ﷺ) saw a man who had been put in the shade and saw a crowd of people around him (in the course of a journey). He said: Fasting while on journey is not part of righteousness
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Bukhari (1946) Sahih Muslim (1115)
In-book reference: 14:95