Sahih Muslim Book 5 – Hadith 238-241
Chapter 33: It is recommended to pray Zuhr at the beginning of its time when there is no intense heat.
Muhammad ibn al-Muthanna and Muhammad ibn Bashar narrated to us, both on the authority of Yahya al-Qattan and Ibn Mahdi - Ibn al-Muthanna said: Yahya ibn Sa`id narrated to me - on the authority of Shu`bah, who said: Simaak ibn Harb narrated to us, on the authority of Jabir ibn Samurah, who said: Ibn al-Muthanna said: Abd al-Rahman ibn Mahdi narrated to us, on the authority of Shu`bah, on the authority of Simaak, on the authority of Jabir. Ibn Samura said: The Prophet, may Allah bless him and grant him peace, used to pray the noon prayer when the sun had declined. (Sahih Muslim Book 5 – Hadith 238)
Khabbab reported:
We complained to the Messenger of Allah (ﷺ) (the difficulty of) saying prayer on the intensely heated (ground or sand), but he paid no heed to our complaint. (Sahih Muslim Book 5 – Hadith 239)
Khabbab reported:
We came to the Messenger of Allah (ﷺ) and we complained to the Messenger of Allah (ﷺ) about (saying prayer) on the extremely heated ground (or sand), but he paid no heed to us. Zuhair said: I asked Abu Ishaq whether it was about the noon prayer. He said: Yes. I again said whether it concerned the (offering) of the noon (prayer) in earlier hours. He said: Yes. I said: Did it concern expediting it? He said: Yes. (Sahih Muslim Book 5 – Hadith 240)
Anas b. Malik reported:
We used to say (the noonprayer) with the Messenger of Allah (ﷺ) in the intense heat, but when someone amongst us found it hard to place his forehead on the ground, he spread his cloth and prostrated on it. (Sahih Muslim Book 5 – Hadith 241)
Sahih Muslim Book 5 – Hadith 238-241