The discussion invokes one unit of ten and Zayd's hand. A member of a collection is not the entire collection, and a hand is not the whole person.
The examples show conceptual distinction while raising the question whether “otherness” applies uniformly to all parts and wholes. Calling something a part does not, by itself, demonstrate independent existential separability.
The divine essence is neither a numerical collection nor a body assembled from organs. The examples test the logic of terms; they cannot be used to attribute material composition to God.