The object of a preposition
the subject of a sentence.
n is always

The object of a preposition is the noun or pronoun governed by a preposition. The object of a preposition is usually (but not always) the noun or pronoun to the right of the preposition.

The subject is sometimes called the “naming part” of a sentence or clause. It shows what the sentence is about, or who or what is performing an action in the sentence. The subject is most often a noun, pronoun, or noun phrase.

Explanation:

Please stay safe!

the eye wink at the hand; yet let that be / which the eye fears, when it is done, to see.