Al-Saffar narrated from Ahmad ibn Muhammad, from Ali ibn Al-Hakam, from Ziyad ibn Abi Al-Halal, from Abdullah ibn Abi Ya'fur. He said: I said to Abu Abdullah عليه السلام: "What do you say about the blood of fleas?" Imam عليه السلام said: "There is no harm in it." I asked: "But it may become excessive and spread greatly." Imam عليه السلام said: "Even if it becomes excessive." I asked: "A man finds spots of blood on his garment without knowing about it, then he becomes aware of it but forgets to wash it and prays, then remembers after he has prayed, should he repeat his prayer?" Imam عليه السلام said: "He should wash it, but he does not need to repeat his prayer, unless the amount of blood is equal to a dirham and concentrated in one spot. In that case, he must wash it and repeat the prayer."