A paradox is a statement that has its foundation on logical assertions but leads to logically unacceptable conclusions. Basically, the premises contradict the conclusion of the statement.
On its own, the statement by Moishe the Beadle does not qualify as a paradox. This is because it is possible that questions may receive replies, but the replies may not be understood. In my opinion, the premise that God replies, and the conclusion that we cannot understand the replies, does not seem to be a contradiction. Human understanding of concepts is not guaranteed, and further, the context in which concepts are understood may vary from one individual to the next.
On the other hand, looking at the narrative in relation to subsequent events, suggests, the statement qualifies as a paradox. Eliezer questioned God about His role and responsibility in the Jewish situation. He further concludes that God remained silent to their plight. The paradox, in this case, is, Eliezer expected God to respond in one way or another (as per Moishe’s statement), but according to him, God did not respond at all.
Behind me, I heard the same man asking:
"For God's sake, where is God?"
And from within me, I heard a voice answer:
"Where He is? This is where—hanging here from this gallows …"
The original question had to be edited. A paradox is a statement that seems to be contradictory or ridiculous but is true despite how it sounds. In the book Night, Moishe the Beadle is teaching Eliezer about God and the Jewish beliefs. Eliezer is a devout Jew, wanting to understand the beliefs of his religion and the why behind those beliefs. This statement is one of the teaching moments between Moishe and Elie. While a thought-provoking statement designed to get Eliezer to ponder the picture of God this presents, in my opinion, this is not a good example of a paradox as it is neither contradictory nor ridiculous even if you believe it to be true.