All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
The word Fatwa linguisticly means giving rulings, and in the terminology of scholars it means giving religious rulings with evidence (for whoever asks for it). This includes questions posed on incidents that happened or proposed ones. The word Mufti refers to a person who gives religious rulings; even if one gave a Fatwa only once, he is considered as a Mufti. However, the word Mufti has a special meaning in religious terminology, it refers to the person of knowledge who attends to peoples inquiries and knows all the Qur'anic sciences and deductions by analogy, but it does not refer to someone who knows only one specific issue.
In reality Fatwa means informing people about Allaah's Ruling and the ruling of the Prophet about the question that is asked, that's why our righteous predecessors used to avoid it, pass it over to others and were very conservative in giving a ruling.
'Abdur-Rahmaan Ibn Abu Layla said: 'I have seen 120 companions if one of them is asked about an issue, he refers the questioner to another companion, and the second refers him to the third until gradually he comes back to the first one.' In another narration: 'None of them is asked a question or was presented with a case or asked to give a ruling on a particular matter except that he wished that his other brother had taken over from him [responds in his place].'
Imaam Ahmad said: 'A person should not propose to give religious rulings unless he meets five characteristics:
1) He should have intention, i.e. devote the action sincerely to Allaah. If he is not sincere, there would be no light on him and his words will have no light.
2) He should have tolerance, reverence and serenity.
3) He should be competent and have great knowledge.
4) He should be solvent otherwise people would hate him.
5) He should know the nature of people, i.e. he should have an insight about people's plots, so he should not be naive, and should be cautious about the way people ask questions [intending to cheat and deceive].'
Allaah knows best.