The Ruling on the Imamate of One Who smokes and One Who uses Qat

All praise be to Allah and may peace and blessings be upon His Messenger and his family and Companions, as for what follows:

The Permanent Committee for Religious Research and Legal Rulings read this question which was presented to His Excellency, the General Chief which was referred to them from the Secretariat General for the Organization of Higher Scholars, with the number [151/2] and its text is:

Question :

"It was time to pray and I found a congregation praying, so I approached in order to pray with them, but as I reached them, I saw that the Imam was one of those who smoke or use Suwaikah Al-Musammah, which is known in the southern area as Shammah, or the Qat tree, or all of them mixed together. When I realized this, I left and prayed by myself. Some of the worshippers said that I was wrong. Was I wrong, and was it permissible to pray behind the like of such people, or was my prayer alone correct? I only did this as a result of personal judgment, although - all praise be to Allah - I am not one who uses such things as these, and this is due to success granted by Allah and from His Bounty. Should such a person as this put himself forward to lead the people in prayer?"

Answer:

The Committee answered as follows:
"Smoking is Haram and continual smoking and addiction to it is even more strongly forbidden, because it is from Al-Khaba'ith, about which Allah, the Most High says:
And prohibits them as unlawful Al-Khaba'ith (i.e. all evil and unlawful things, deeds, beliefs, persons, foods etc.).
(It is also forbidden) due to the harm which it causes, and the Prophet said:
"Let there be no harm and no reciprocating harm. It is not permissible for one who smokes to act as Imam in prayer, unless it is to lead other smokers or those who do worse in prayer. However, you were wrong in leaving the prayer with him and praying alone, because performing the five prayers in congregation is obligatory, according to the evidences from the Qur'an and the Sunnah which prove this. What you should have done when you left the prayer because you realized that the Imam was a smoker or a user of some other such thing, was to find another congregation, in order to pray with them. If your circumstances did not permit you find another congregation, then you should have prayed with such an Imam, in order to guard the obligatory prayer in congregation, based upon the legal evidence which has been reported, which proves that prayer behind the sinners is correct. And may peace and blessings be upon our Prophet, Muhammad and upon his family and Companions."

Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 2 Pages 415-416