Can he open a store to do cupping in return for payment?

The scholars differed concerning the earnings of a cupper –
is that makrooh or permissible without being makrooh? The reason why they
differed is that they differed in their understanding of the ahaadeeth that
have been narrated concerning that. 

Among the ahaadeeth which describe the earnings of a cupper
as makrooh are the following: 

1 – The Prophet (peace and blessings of Allaah be upon
him) said: “The earnings of a cupper are khabeeth (evil).” Narrated by
Muslim (1568) 

2 – The Prophet (peace and blessings of Allaah be upon
him) said: “The worst of earnings are the wages of a prostitute, the price
of a dog and the fee of a cupper.” Narrated by Muslim (1568). 

3 – It was narrated that Abu Hurayrah (may Allaah be pleased
with him) said: The Messenger of Allaah (peace and blessings of Allaah
be upon him) forbade the earnings of a cupper. Narrated by Ahmad (7635),
al-Nasaa’i (4673), Ibn Maajah (2165); classed as saheeh by al-Albaani in
Saheeh al-Nasaa’i. 

Among the ahaadeeth which mention a concession allowing that
are the following: 

1 – The report narrated by al-Bukhaari (2102) and Muslim
(1577) from Anas ibn Maalik (may Allaah be pleased with him) who said: Abu
Taybah treated the Messenger of Allaah (peace and blessings of Allaah
be upon him) with cupping and he ordered that he given a saa’ of dates. 

2 – The report narrated by al-Bukhaari (2103) and Muslim from
Ibn ‘Abbaas (may Allaah be pleased with him) who said: “The Prophet
(peace and blessings of Allaah be upon him) was treated with cupping and he
gave something to the one who treated him. If it had been haraam he would
not have given him anything.” This is the wording of al-Bukhaari. He also
narrated another version (2278) which says: “And he gave the cupper his
wages; if he knew that it was makrooh he would not have given him anything.”
And Muslim (1202) narrated: “If it were haraam the Prophet (peace and
blessings of Allaah be upon him) would not have given him anything. 

The majority of scholars are of the view that when all of
these ahaadeeth are taken together, the prohibition may be understood as
meaning that it is makrooh. 

Ibn Qudaamah (may Allaah have mercy on him) said: It is
permissible to hire a cupper to treat one with cupping, and his earnings are
permissible. This is the view favoured by Abu’l-Khattaab and it is the
opinion of Ibn ‘Abbaas. It is also the view of Maalik, al-Shaafa’i and
as-haab al-ra’y. Al-Qaadi (i.e., Abu Ya’la, who was a Hanbali) said: The
wages of a cupper are not permissible, and he mentioned that Ahmad stated
that in several places and said: If he is given something without a (formal)
contract or stipulating that, he may take it and dispose of it in feeding
his animals or feeding his slaves or on the tools of his trade, but it is
not permissible for him to consume it. Among those who regarded the earnings
of a cupper as makrooh were ‘Uthmaan, Abu Hurayrah, al-Hasan and al-Nakha’i,
because the Prophet (peace and blessings of Allaah be upon him) said:
“The earnings of a cupper are khabeeth (evil)” (narrated by Muslim) and he
said of the earnings of a cupper: “Feed it to your camel and your slaves”
(narrated by Ahmad and al-Tirmidhi (1277), classed as saheeh by al-Albaani
in Saheeh al-Tirmidhi. 

The fact that this is permissible and not haraam is also
indicated by the report narrated by Ibn ‘Abbaas who said: The Prophet
(peace and blessings of Allaah be upon him) was treated with cupping and he
gave the cupper his wages; if he knew it was haraam he would not have given
it to him.” Agreed upon. According to another version: “if he knew it was
khabeeth (evil) he would not have given it to him.” The words of the Prophet
(peace and blessings of Allaah be upon him) regarding the earnings of a
cupper, “Feed it to your slaves,” indicates that his earnings are
permissible, because it is not permissible for him to feed his slaves with
food that is haraam to eat, for slaves are human and the things that Allaah
has forbidden are forbidden to them just as they are forbidden to those who
are free. Calling it khabeeth (evil) earnings does not necessarily mean that
it is haraam, because the Prophet (peace and blessings of Allaah be
upon him) called garlic and onions khabeeth even though they are
permissible. 

Rather the Prophet (peace and blessings of Allaah be
upon him) disliked that for one who is free because this type of work is not
befitting for a free man. The fact that the Prophet (peace and
blessings of Allaah be upon him) told him to give it to his slave indicates
that it is permissible. The prohibition on eating it is to be understood as
meaning that it is makrooh, not haraam. End quote from al-Mughni
(6/133). 

Based on this, there is no sin on you if you open this shop,
and the fees that you take from people for that are not haraam. 

And Allaah knows best.