Bulugh al-Maram 2 The Book of Prayer كتاب الصلاة 358

وَفِي لَفْظٍ لِمُسْلِمٍ: { كُنَّا نَجْمَعُ مَعَهُ إِذَا زَالَتِ اَلشَّمْسُ, ثُمَّ نَرْجِعُ, نَتَتَبَّعُ اَلْفَيْءَ } 1 . 1 – صحيح. رواه مسلم (860) (31).

And in a narration of Muslim: “We used to offer the Friday prayers with him [Allah’s Messenger (صلى الله عليه وسلم)] when the sun passed the meridian. We would then return and try to find the afternoon shadow.