Bulugh al-Maram
Book 2, Hadith 362
Arabic hadith text
وَفِي لَفْظٍ لِمُسْلِمٍ: { كُنَّا نَجْمَعُ مَعَهُ إِذَا زَالَتِ اَلشَّمْسُ, ثُمَّ نَرْجِعُ, نَتَتَبَّعُ اَلْفَيْءَ } 1 .1 - صحيح. رواه مسلم (860) (31).
Translation
And in a narration of Muslim
"We used to offer the Friday prayers with him [Allah's Messenger (ﷺ)] when the sun passed the meridian. We would then return and try to find the afternoon shadow.