Imagine what it would mean if we Orthodox Jews could actually prove our Oral Torah from Sinai? Wouldn’t it be amazing! Well, as it turns out, we can. The following is just a little piece I wrote about a while back concerning the Ethiopian Jews. Enjoy.
. . .Imagine, for a moment, what it would mean to the veracity of the Oral Torah, if we found a ritual from its earliest records (the Mishnah) preserved by an isolated community of Jews who left Yisrael over 2,000 some years ago? Could such a thing exist? As it turns out, the answer is yes!
The people are ancient, they left Yisrael centuries before the birth of any famous Chazal (sages), the laws they have preserved cannot be derived from the Written Torah with pure logic alone, and, most importantly, the oral traditions of which they follow, were recorded by their own memory way before any rabbinic writing had taken shape.
Who are these people? The Abyssinian Christians. Keep in mind, however, that I do NOT approve their stance as Christians. Remember that these people were once fellow Jews who worshipped HaShem (G-d), in which they have passed down the oral traditions in spite of that. Therefore, I won’t touch on their current beliefs as Christians, just their ancient past.
So these people have in them a built-in safe of Oral Law. And the code is in the Mishnah. The numbers to unlocking the safe are the unique altar practices which exist nowhere else outside of Pharisaic Judaism.
It would be wise, however, to note that these people must have left prior to the destruction of the First Beit HaMildash (First Temple), as they have no tradition regarding any of the publicly ordained fasts - they specifically only follow the “Sigd,” a day to express their longing to return to Eretz Yisrael. According to Yemenite Jewish tradition, the community is a direct result of our bondage in Egypt, as Ethiopia was a safe haven for slaves.  When they learned of the Brit of Sinai, they immediately accepted it upon themselves.
Christianity was introduced to the people in 331 CE, by a Syrian monk. According to a very rare Ethiopian manuscript, the Tigrayan fortress of Magdala, we’re told that: ‘Christianity was introduced into Abyssinia 331 years after the birth of [Jesus] by Abuna Salam, whose former name was Frumemtos or Frumemtius. At that time the Ethiopian kings reigned over Axum. Before the Christian religion was known in Ethiopia, half the inhabitants were Jews who observed the Law; the other half were worshipers of Sando, the dragon.’