Wa `alaykum as-salamu wa rahmatullahi wa barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
Responding to your question, Dr. Salah Al-Sawy, the President of the Sharia Academy and the Secretary General for the Assembly of Muslim Jurists in America, states:
Voluntary work is one of the basic righteous deeds which deserve rewards in the Hereafter, especially those intended for the pleasure of Allah. The basic legal ruling is that voluntary work is not offered for a monetary compensation.
Allah the Almighty confirms this in the Qur’an by saying, “Follow those who ask of you no fee, and who are rightly guided.” (Ya-Sin 36: 21) Allah further blamed the unbelievers for not following the path of Allah’s Messengers by saying, “Or do you (Muhammad) ask a fee from them so that they are heavily taxed?” (At-Tur 68:46)
The Western societies encourage non-profit voluntary work by making it one of the avenues for tax expenditures. Many countries and places were rescued due to such voluntary works and many hungry people were fed and many difficulties and sufferings were alleviated due to those acts.
The Muslim nation is worth hastening in participating those acts which raise the emblem of this religion high, the true religion that Allah has chosen for His slaves up to the Day of Judgment.
Allah Almighty knows best.