According to longtime Inside the Vatican contributor William Doino, who discovered the testimony in an archive, maintained by Tel Aviv University, "the testimony has apparently been forgotten, because, as far as I know, no leading Holocaust authority or biographer of Pius XII has ever cited it."
As the article reports, the Jewish author attended a papal audience in the autumn of 1941. He entered the papal chamber along with numerous other people, including a group of German soldiers. (It was common for soldiers to visit the Pope early in the war era. Later, when Hitler learned of what the Pope told them, he put an end to this practice.)
The author was the final individual to approach the Pope that day. He wanted to tell Pius about a group of Jews who were being interned by Italy’s Fascist government on an island, in danger of starvation. He tried to speak in broken Italian, but the Pope invited him to use his native language, assuming that it would be German. "You are German, too, aren't you?" asked the Pope. The author then explained that he was born in Germany, but he was a Jew.
Pius invited the author to finish his story. He listened intently then said: "You have done well to come to me and tell me this. I have heard about it before. Come back tomorrow with a written report and give it to the Secretary of State who is dealing with the question. But now for you, my son. You are a young Jew. I know what that means and I hope you will always be proud to be a Jew!"
Pius then raised his voice so that everyone in the hall - including the German soldiers - could hear it and said (in a "pleasant voice"): "My son, whether you are worthier than others only the Lord knows, but believe me, you are at least as worthy as every other human being that lives on our earth! And now, my Jewish friend, go with the protection of the Lord, and never forget, you must always be proud to be a Jew!"