Sunan Abi Dawud 4821
سنن أبي داود#4821SahihNarrated AbuHurayrah: AbulQasim (ﷺ) said: When one of you is in the sun (Shams)--Makhlad's version has "fay'"--and the shadow withdraws from him so that he is partly in sun and partly in shade, he should get up
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 ArnautHasan Lighairihi
Zubair Ali ZaiHasan
In-book reference: 43:49