The reciter: And Abu Bakr ibn Abi Shaybah narrated to us, and Abdullah ibn Idris narrated to us from Shu'bah from Abu Imran from Abdullah ibn al-Samit from Abu Dharr, who said:
My friend (the Holy Prophet) bade me to hear and obey (the ruler) even if he is a slave having his feet and arms cut off, and observe prayer at its prescribed time. (And further said): It you find people having observed the prayer, you in fact saved your prayer, otherwise (if you join with them) that would be a Nafl prayer for you.
إن خليلي أوصاني أن أسمع وأطيع وإن كان عبدا مجدع الأطراف، وأن أصلي الصلاة لوقتها فإن أدركت القوم وقد صلوا كنت قد أحرزت صلاتك وإلا كانت لك نافلة Sahih Muslim 648c.