From him, from Uthman ibn Isa, from Sama'ah, from Abu Abdillah عليه السلام, peace be upon him, who said: I said to Imam al-Sadiq عليه السلام: “When is the sacrifice to be slaughtered?” Imam عليه السلام said: “When the (just) imam has finished (the Eid prayer and turned away).” I asked: “What if I am in a land where there is no (just) imam, and I lead them in prayer in congregation?” Imam عليه السلام said: “(Do sacrifice) When the sun has risen fully (when it has ascended).” And Imam عليه السلام said: “There is no harm in you praying alone, but there is no (valid) prayer except with an (just) imam.”