Does a donor to associations for da'wah (calling to Islam) or for treating the poor free of charge receive the reward for da'wah and guidance, or the reward for treating the poor?

If you donate to trustworthy charitable organizations that support the propagation of good, assist those in need, and care for Islamic callers (du'at) and doctors, then you are a partner in the reward of those good deeds, and you will receive the reward of the callers and doctors. The proof for this is the saying of the Prophet, peace and blessings be upon him: "Whoever equips a warrior in the cause of Allah has indeed fought, and whoever looks after a warrior's family well in his absence has indeed fought." Scholars have clarified that whoever assists a believer in a righteous deed receives a reward similar to that of the doer, and similarly, whoever assists in acts of disobedience to Allah bears a burden similar to that of the doer.