question #3 Sahih Muslim 648a, Book 5, Hadith 298 : How can performing a prayer with rulers who delay it serve as a supererogatory act for an individual?

The Messenger of Allah (ﷺ) said to me: How would you act when you are under the rulers who would delay the prayer beyond its prescribed time, or they would make prayer a dead thing as far as its proper time is concerned? I said: What do you command? He (the Holy Prophet) said: Observe the prayer at Its proper time, and if you can say it along with them do so, for it would be a superetogatory prayer for you. Khalaf (one of the narrators in the above hadith) has not mentioned” beyond their (prescribed) time”.