Rav Moshe and his son Rav Chanoch were captured by gentiles in the days of the Rashbash close to year 4750 more or less, because the Ishmaelite king sent his commander to conquer the ships of Edom etc., and they surrounded toward Greece and found a ship in which were five great sages who went from the city of Bari to the city of Sefastoon to bring in a bride. He conquered the ship and captured the sages.
Two were: Rav Chushiel the father of Rav Chananel, and the second was Rav Moshe mentioned above whom he captured with his wife, and his son Rav Chanoch was still a youth, and the third was Rav Shemarya bar Elchanan, and the fourth I do not know his name. He sought to force Rav Moshe's wife and to abuse her because she was very beautiful in appearance. She cried out to Rav Moshe her husband in the Holy Tongue asking him if those who drown in the sea are revived in the resurrection, and he replied, "HaShem said, 'From Bashan I will bring back, I will bring back from the depths of the sea.'" When she heard, she threw herself into the sea and drowned.
These sages did not reveal to anyone their nature and wisdom. He sold Rav Shemarya in Alexandria of Egypt and from there he went up to Egypt and became a leader. He sold Rav Chushiel in Africa on the seashore and from there he went up to the city of Alexandria and was a leader there, and there he fathered Rav Chananel his son. The third one he brought to Cordoba and sold there Rav Moshe and Rav Chanoch his son, and the people of Cordoba redeemed them.
About that same time he was a witness, and there was there a judge and teacher, Rabbi Natan, who was greatly pious but the people of Sefard were not experts in the words of our sages of blessed memory, and despite this, in that small amount that they knew, they would make midrash and commentaries. Rabbi Natan was explaining every water immersion in Tractate Yoma and did not know how to explain it. Rav Moshe was sitting in the corner like a servant and arose before Rabbi Natan and said, "Rabbi, these immersions have explanations." When he and his students heard his words, they were amazed at each other and asked him to explain the law, and he explained it to them properly, and each one of them asked him questions about all the doubts they had, and he answered in the breadth of his wisdom.
The litigants were outside the study hall because they had no permission to enter until the students completed their lesson. That day Rabbi Natan went out and the litigants went after him and said, "I do not know how to be a judge, and this one dressed in sackcloth and the guest is my teacher and I am his student. I will be from today on, and you shall appoint him over the congregation of Cordoba to judge," and so they did.
They gave him a great stipend from the congregation and honored him with expensive garments and a chariot. The commander wanted to reverse his sale but the king did not allow him because the king was very glad when he heard that the Jews in his kingdom did not need the people of Babylon. The word was heard in all of Spain and the west, and students came to learn, and all the questions that they used to ask from the yeshivot they asked from him.
Rav Moshe married into the Platia family which was the greatest of all the families of the Cordoba congregation, and he took a wife from them for his son Rav Chanoch, and the daughter of Rav Chanoch was married to one of the sons of Platia. Rav Moshe had many students, among them Rav Yosef bar Yitzchak Shatnas ben Avitor. [Yuchsin in the order of the Geonim, generation 7, and in Seder HaKabbalah of the Rema.
And below is ben Aviador.]