Al-Adab Al-Mufrad, Book 47, Hadith 1174 (English)

Qays related that his father arrived while the Messenger of Allah, may Allah bless him and grant him peace, was speaking. He stood in the sun and the Prophet told him to move to the shade.

حَدَّثَنَا مُسَدَّدٌ، قَالَ‏:‏ حَدَّثَنَا يَحْيَى، قَالَ‏:‏ حَدَّثَنَا إِسْمَاعِيلُ بْنُ أَبِي خَالِدٍ قَالَ‏:‏ حَدَّثَنِي قَيْسٌ، عَنْ أَبِيهِ، أَنَّهُ جَاءَ وَرَسُولُ اللهِ صلى الله عليه وسلم يَخْطُبُ، فَقَامَ فِي الشَّمْسِ، فَأَمَرَهُ فَتَحَوَّلَ إِلَى الظِّلِّ‏.‏

sunnah.com