question #1 Sahih Muslim 648c, Book 5, Hadith 300 : What is the significance of obeying a ruler, even if he is of low status or has physical disabilities, in Islamic teachings?

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.