As for the hadith, al-Haythamī said (8/60):

“Ahmad narrated it, and its narrators are narrators of the authentic collections, apart from Kathīr ibn Abī Kathīr, who is trustworthy.”

Its narrator Qatādah (may Allah have mercy on him) acted upon this hadith. ʿAbd al-Razzāq narrated in al-Muṣannaf (11/25), from Maʿmar, from him, that he said:

“It is disliked for a person to sit with part of his body in the shade and part in the sun.”

Just before this, he also narrated from Maʿmar, from Muḥammad ibn al-Munkadir, from Abū Hurayrah, who said:

“If one of you is in the shade and it recedes from him, let him stand up, for it is Satan’s sitting-place.”

ʿAbd al-Wārith corroborated him, saying: Muḥammad ibn al-Munkadir narrated to us with the same report, but he attributed it to the Prophet. Ahmad narrated it (2/383).

The narrators of both this report attributed to the Companion and the report attributed to the Prophet are trustworthy.

Sufyān differed from them in its chain of transmission, saying: Muḥammad ibn al-Munkadir said: “Someone who heard Abū Hurayrah told me that Abū al-Qāsim said …” He then cited it as a report attributed to the Prophet, similar in meaning, with the wording:

“If one of you is in the sun—in another version, in the shade—and the shade recedes from him, so that part of him is in the sun and part in the shade, let him stand up.”

Abū Dāwūd narrated it (4821), and al-Bayhaqī (3/236) narrated it through him.

I say: Sufyān’s version is perhaps more correct, both in its connected chain and in its attribution to the Prophet. As for its connectedness, Ibn al-Munkadir did not hear from Abū Hurayrah, as they stated in his biographical notice. As for its attribution to the Prophet, this is supported by the aforementioned narration of Abū ʿIyāḍ from Abū Hurayrah; perhaps this Abū ʿIyāḍ was the intermediary between Ibn al-Munkadir and Abū Hurayrah.

Ismāʿīl ibn Muslim differed from all of them, saying: from Muḥammad ibn al-Munkadir, from Jābir: