´Khalid bin Dinar Abu Khaldah said:` "I heard Anas bin Malik say: 'When it was hot, the Messenger of Allah (ﷺ) would wait until it cooled down to pray, and when it was cold he would hasten to pray.'"
Hadith Referenceسنن نسائي / كتاب المواقيت / 500
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح بخاري
1؎: In the narration of Sahih Bukhari, one of the narrators has interpreted «صلاة» as "Jumu'ah" (Friday prayer), because in another narration of this same hadith, it is mentioned that a questioner had asked Anas radi Allahu anhu specifically about Jumu'ah (Fath al-Bari). The author has deduced from its general wording «الصلاة», and also from the fact that the customary time for Jumu'ah and Dhuhr is the same.
2؎: That is, due to the intensity of the heat, they would delay it from its customary time to such an extent that the shade of the walls would become sufficient for people to walk in it and reach the mosque, and the severity of the heat would subside.
Explanation & Benefits
Hafiz Muhammad Ameen
500. Commentary: The meaning of "ibrad" is to perform the prayer at a cooler time, but in reality, what is meant is not the truly cool time, because that would be near sunset in the summer. Rather, what is intended is a time somewhat cooler compared to midday—that is, when the shadow of the walls becomes sufficient for placing one's feet. In winter, the days are shorter, the time is less, and there is no reason to delay from the earliest time; therefore, the Prophet (sallallahu alayhi wa sallam) would perform the prayer early. For further details, refer to the introduction of this very book.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 500