Praise be to Allah.
If the matter is as described in the question and the shar’i conditions of using the daff only in a wedding party will be adhered to, then there is nothing wrong with bringing a female singer and paying her for her work.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said:
As for giving money to women who play the daff, there is nothing wrong with it, because that is a payment for permissible work. But giving money to women who play other kinds of drums is not permissible, because that is payment for haraam work. The Prophet (peace and blessings of Allaah be upon him) said: “When Allaah forbids a thing, he forbids its price.” Narrated by Ibn Hibbaan, 4938; classed as saheeh by al-Albaani in Ghaayat al-Maraam, 318.
End quote. Liqa’ al-Baab il-Maftooh, 1/580. See al-Liqa’ al-Shahri, 235
We must point out here that beating the daff at wedding parties and paying someone to do that is permissible in principle, but it may be accompanied by haraam or makrooh things which make it disallowed.
Shaykh Muhammad ibn Ibraaheem (may Allaah have mercy on him) said:
Beating the daff at weddings is permissible according to sharee’ah so as to announce the wedding, but if other evil consequences happen as a result of that, then it is not allowed. End quote.
Majmoo’ al-Fataawa, 10/218
Examples of that include dancing to this daff.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said:
Dancing is makrooh, especially if there is the fear of fitnah (temptation) as a result, because sometimes the dancer may be young and beautiful, and her dancing may provoke desire even in women. End quote.
Liqa’ al-Baab al-Maftooh, 1/580
See also question no. 5000 and 9290
Another example is extravagance in the fee paid.
The fee paid to the woman who beats the daff should be reasonable, not extravagant. Allaah says, forbidding extravagance (interpretation of the meaning):
“and waste not by extravagance. Verily, He likes not Al‑Musrifoon (those who waste by extravagance)”
[al-An’aam 6:141]
This extravagance may be a cause of blessing being taken away from this marriage. It is narrated that the Prophet (peace and blessings of Allaah be upon him) said: “The woman who brings the greatest blessing is the one whose wedding arrangements are the most moderate.” Narrated by Ahmad, 24595; classed as saheeh by al-Haakim, and al-Dhahabi agreed with him. Al-‘Iraaqi said in Takhreej Ahaadeeth al-Ihya’: its isnaad is jayyid.
But it was classed as da’eef by al-Haythami in Majma’ al-Zawaa’id, 7332; and by al-Albaani in al-Silsilah al-Da’eefah, 1117.
And Allaah knows best.
Comment