'Abdu'r-Rahman ibn Ziyad ibn An'am al-Ifriqi said, "My father told me that they were taking part in a sea raid in the time of Mu'awiya. He said, 'Our ship was right up against the ship of Abu Ayyub al-Ansari. When it was time for our midday meal, we invited him and he came over. He said, "You invited me, but even though I am fasting, I cannot avoid accepting your invitation because I heard the Messenger of Allah, may Allah bless him and grant him peace, say, 'A Muslim owes six things to his brother. If he neglects any of them, he has neglected an obligatory duty owed to his brother. He should return his greeting when he greets him. He should accept when he gives him an invitation. He should ask for mercy on him when he sneezes. He should give him good counsel when he asks him for advice.'"'"