Abu Al-Bakhtari (may Allah have mercy on him) says that on the occasion of the Battle of Siffin, Hazrat Ammar bin Yasir (may Allah be pleased with him) said, "Bring me a cup of milk, because the Noble Prophet (peace and blessings be upon him) had said, 'The last sip you will drink in this world will be a sip of milk.'" So milk was brought to him, he drank it, then advanced and was martyred.