Where does this plural come from?

Question

I am translating a medieval Latin text about the donation of a monastery. In the text there is this sentence:

Idcirco noverit omnium fidelium sanctae dei ecclesiae nostrumque praesentium scilicet et futurorum solertia atque industria, quia nos pro mercedis nostrae augmento concessimus monasterio quod dicitur Hasereod,..., quasdam res proprietatis nostrae,...

I would translate this as follows:

For the reason that he (god as by the earlier text) knows the present and certainly also the future skills and works of all faithful of our holy church of god, we have, to the augmentation of our reward, donated the monastary which is called Hasereod,..., part of our property,...

I do not understand where the plural from "quasdam" suddenly comes from. Could you explain?

Answer 1

It is accusative plural, agreeing with res. "We have donated to the monastery which is called H. certain things (that were part) of our property".