'A man once invited the Commander of the Faithful, 'Ali (AS) for a meal, so Imam said to him, 'I will accept your invitation provided yo fulfil three conditions.' The man asked, 'And what are they, O Commander of the Faithful?' to which he replied, 'Do not bring any special food from outside for me, do not preserve anything in the house especially for me, and do not impose any difficulty on your family.' The man replied, 'You shall have that O Commander of the Faithful' and 'Ali b. Abi Talib accepted his invitation.'