Dimitry,

> Donors are also plural. I can't understand how yesa.m and tesa.m can
> refer to requisites. Would you translate the sentence?

I should have been a little more clear. It refers both to the 'donors' and
the requisites. Of the requisites of the donors.

Here is an out of context translation (which I can't gaurantee as correct):

Of those whose necessities (parikkhaaraana.m), such as robes, alms-food,
dwellings, medicines for the sick, we make use of, those services (kaaraa)
will bear them great fruit and benefit, and this our going forth will be not
in vain but fruitful and productive.

Sean