Onkelos the proselyte was a son of Emperor Hadrian's sister. To him refers the verse in the Bible, which says: "He declareth His word unto Jacob, His statutes and His ordinances unto Israel. He hath not dealt so with any nation" (Ps. 147.19-20). I will explain to you the meaning of the verse.

Onkelos wanted to embrace Judaism and learn the Torah, but he stood in fear of his uncle the Emperor. So he went to the Emperor and said to him: "My dear uncle, I want to go out into the world to do business, and at the same time I want to learn a trade. I want to see the world and find out how the people earn their living; Here at home I am like a domestic calf, which knows nothing of the world."

The Emperor replied: "What do you want to do? Do you want to become a merchant and make money? You had better remain at home. I will give you all my treasures, and you will have plenty of money without having to travel."

But he replied: "Dear uncle, I wish to buy merchandise, and desire your advice in the matter of what to buy and what not to buy."

The Emperor said: "If you have set your mind on buying goods, then buy those goods which are very low in the market and which no one wants to buy. The time will come when those goods will rise in price and you will make a very good profit."

So he departed and went to Palestine, where he studied Torah.

Not long afterwards, R. Eliezer and R. Joshua saw him and said to one another: "Look at Onkelos, how ill he looks. He must have been studying the Torah, for he who studies the Torah becomes pale and weak."

When he came up to the two rabbis, he asked them many questions, which they answered. Then he returned home to the Emperor.

When the Emperor looked at him, he asked him: "My dear boy, why do you look so ill? You must have lost a great deal of money in your business, or else someone must have done you some harm."

He replied: "No, who would dare todo me harm as long as you are alive? Everyone in the world is afraid of you."

"Why then," said the Emperor, "are you looking so badly?"

"My Lord. I will tell you why I am looking so ill. I have been studying the Torah, and what is more, I have had myself circumcised."

The Emperor said: "Who told you to do it?"

Onkelos replied: "I consulted you and followed your advice."

The Emperor said: "When did I advise you to do this?"

He replied: "I told you that I wanted to go into the world to buy merchandise, and you advised me to buy the goods which were the lowest in the market, as the time would come when they would rise in price and I would make huge profits. Accordingly, I traveled throughout the world and I found no nation on earth which was held in lower esteem than the people of Israel. Surely that is the people which in the future will be very highly regarded, as we find the prophet Isaiah (49.7) saying: 'To him who is despised of men, to him who is abhorred of nations, to a servant of rulers: kings shall see and arise, princes and they shall prostrate themselves.' Therefore I bought these goods, which are now very low in the market, but will afterwards rise very high. As you advised me so did I act."

The Emperor said: "But why did you adopt Judaism and embrace the covenant of Abraham?

He replied: "Because I wanted to study the Torah." Then the Emperor said: "You could have studied the Torah without becoming a Jew."

Onkelos replied: "I will give you an example. One does not entrust the guidance of a ship to a man unless he can put up the mast and turn it in the direction of the wind, in the proper way. In the same way, no one can study the Torah with the hope that it will remain with him permanently unless he embraces Judaism, as it is stated in the Bible: 'He declareth His word unto Jacob, His statutes and His ordinances unto Israel. He hath not dealt so with any nation' (Ps. 147.19-20). This means that God speaks and gives His Law and His statutes only to those who are circumcised as Jacob was, and not to the other nations who are not Jews. Therefore I was bound to embrace Judaism."