Hadith 2412

It is reported that Abu Dharr said, "My dear friend, may Allah blesshim and grant him peace, enjoined three things on me:
'Hear and obey, evenif the ruler is a slave with his limbs amputated. When you cook a stew, puta lot of water in it and then go and see the people of a neighbouring houseand give them a reasonable amount of it. Pray the prayers at their properprayers. Then if you find that the imam has already prayed, you have guardedyour prayer (by already having performed it). If not, it is a supererogatoryprayer (since you have done it again)."