Can a woman request non-material things as part of her Mahr, such as feeding orphans, instead of material things like gold?

The basic principle concerning the mahr (dowry) is that it must be wealth, meaning anything that is dealt with and benefited from in a lawful manner. This includes money, properties, and permissible usufructs. There is no limit for the minimum or maximum mahr; it is valid with whatever the spouses agree upon, and it must be paid to the woman for her benefit.

Accordingly, if feeding orphans is intended solely for your husband's reward and without you receiving any mahr, then it is not permissible, because in this case, the marriage would be concluded without a mahr. However, if there is another mahr specified for you, then feeding orphans is considered a valid condition that must be fulfilled, and the marriage is valid.

And if your intention is for your husband to feed [the orphans] on your behalf, meaning that you are the one providing the food, then this is permissible, and the mahr would be the value of the meals, provided that the number of orphans is precisely determined.