It discusses in the Talmud of Sanhedrin that Akiva is from the descendants of the evil general Sisera who tried to destroy the Jewish people

§ In connection to the above incident concerning the poverty of scholars and their potential to become wealthy through remarkable circumstances, the Gemara relates an incident: Rabbi Akiva became betrothed to the daughter of bar Kalba Savua. When bar Kalba Savua heard about their betrothal, he took a vow prohibiting her from eating all of his property. Despite this, she went ahead and married Rabbi Akiva.

In the winter they would sleep in a storehouse of straw, and Rabbi Akiva would gather strands of straw from her hair. He said to her: If I had the means I would place on your head a Jerusalem of Gold, a type of crown.

Elijah the prophet came and appeared to them as a regular person and started calling and knocking on the door. He said to them: Give me a bit of straw, as my wife gave birth and I do not have anything on which to lay her. Rabbi Akiva said to his wife: See this man, who does not even have straw. We should be happy with our lot, as we at least have straw to sleep on. She said to him: Go and be a student of Torah.

He went and studied Torah for twelve years before Rabbi Eliezer and Rabbi Yehoshua. At the completion of the twelve years, he was coming home when he heard from behind his house that one wicked person was saying to his wife: Your father behaved well toward you. He was right to disinherit you. One reason is that your husband is not similar to you, i.e., he is not suitable for you. And furthermore, he has left you in widowhood in his lifetime all these years. She said to him: If he listens to me, he should be there for another twelve years. Rabbi Akiva said: Since she has given me permission through this statement, I will go back and study more.

He turned back and went to the study hall, and he was there for another twelve years. Eventually he came back accompanied by 24,000 pairs of students. Everyone went out to greet him, as he was by then a renowned teacher, and she too arose to go out to greet him.

That wicked person said to her: And to where are you going? As she was excessively poor, she was not dressed in a grand manner, as fit for the wife of one so esteemed. She said to him: “A righteous man regards the life of his beast” (Proverbs 12:10); he knows that I am in this state as a result of my dedication to him.

She came to present herself before Rabbi Akiva, but the Sages tried to fend her off, as they were unaware of her identity. He said to them: Leave her. Both my Torah knowledge and yours are hers.

When bar Kalba Savua heard that the famous man was his son-in-law, he came before halakhic authorities and requested the dissolution of his vow, and it was dissolved.

(2) What were Akiva's beginnings? It is said: Up to the age of forty, he had not yet studied a thing. One time, while standing by the mouth of a well in Lydda, he inquired, "Who hollowed out this stone?" and was told, "Akiva, haven't you read that 'water wears away stone' (Job 14:19)? - it was water falling upon it constantly, day after day." At that, Rabbi Akiva asked himself: Is my mind harder than this stone? I will go and study at least one section of Torah. He went directly to a schoolhouse, and he and his son began reading from a child's tablet. Rabbi Akiva took hold of one end of the tablet, and his son of the other end. The teacher wrote down alef and bet for him, and he learned them; alef to tav, and he learned them; the book of Leviticus, and he learned it. He went on studying until he learned the whole Torah. Then he went and sat before Rabbi Eliezer and Rabbi Joshua. "My masters," he said, "reveal the sense of Mishnah to me." When they told him one halakhah, he went off to reason with himself. This alef, he wondered, what was it written for? That bet - what was it written for? This teaching - what was it uttered for? He kept coming back, kept inquiring of Rabbi Eliezer and Rabbi Joshua, until he reduced his teachers to silence.

R. Akiva was a shepherd of Kalba Savua. The latter’s daughter, seeing how modest and noble he was, said to him, “Were I to be betrothed to you, would you go away to [study at] an academy?” “Yes”, he replied. She was then secretly betrothed to him and sent him away. When her father heard, he drove her from his house and forbade her by a vow to have any benefit from his estate.

[R. Akiva] departed, and spent twelve years at the academy. When he returned home, he brought with him twelve thousand disciples. He heard an old man saying to her, “How long will you lead the life of a living widowhood?” “If he would listen to me”, she replied, “he would spend [in study] another twelve years”. Said [R. Akiva]: “It is then with her consent that I am acting”, and he departed again and spent another twelve years at the academy.

When he finally returned, he brought with him twenty-four thousand disciples. His wife heard and went out to meet him, when her neighbours said to her, “Borrow some respectable clothes and put them on”, but she replied, “A righteous man knoweth the life of his beast”. On approaching him she fell upon her face and kissed his feet. His attendants were about to thrust her aside, when [R. Akiva] cried to them, “Leave her alone, mine and yours are hers”.

Her father, on hearing that a great man had come to the town, said, “I shall go to him, perchance he will invalidate my vow”. When he came to him, [R. Akiva asked], “Would you have made your vow if you had known that he was a great man?” “[Had he known]”, the other replied, “even one chapter or even one single halachah [I would not have made the vow]”. He said to him, “I am the man”. The other fell upon his face and kissed his feet and also gave him half of his wealth”.

The daughter of R. Akiva acted in a similar way towards ben Azzai. This is indeed an illustration of the proverb: “Ewe follows ewe, a daughter’s acts are like those of her mother”