Tanna D'vei Eliyahu 11
This is how the Jewish people were in the days of the Judges: They would behave badly, God would give them into the hands of the [non-Jews], and when they repented, immediately God would redeem them.
(1) And the children of Israel again did that which was evil in the sight of the LORD, when Ehud was dead. (2) And the LORD gave them over into the hand of Jabin king of Canaan, that reigned in Hazor; the captain of whose host was Sisera, who dwelt in Harosheth-goiim. (3) And the children of Israel cried unto the LORD; for he had nine hundred chariots of iron; and twenty years he mightily oppressed the children of Israel.
Eliyahu Rabba 89
What is so special about Devorah that she was chosen as Judge for Israel and prophet at that time? Especially since Pinchas Ben Elazar was around in those days?... It is because whether Jew or non-Jew, man or woman, slave or maidservant, the Divine Spirit rests upon people – all according to their actions.
Tosfot, Talmud Nida 50a
Devorah judged, in accordance with God's words to her. Alternatively, she was not a judge but rather a teacher of the laws.
Talmud – Megillah 14a
Another reason: the palm tree has only a little shade. So too, there were only a few scholars in that generation.
Also, there is only one heart in the trunk of the palm tree. So too, in [Devorah's] generation the Jewish people had only one heart for their Father in Heaven.
Midrash – Tanchuma, Behar 3
What is the meaning of "exceedingly" (exceedingly harsh oppression with which the Canaanites oppressed the Jews)? Rabbi Yitzchak said: With humiliating curses and taunting, as it says (Malachi 3:13), "Your words are harsh upon me." Who was fitting to deal with this problem? Devorah."
(53) And a certain woman cast an upper millstone upon Abimelech’s head, and broke his skull. (54) Then he called hastily unto the young man his armour-bearer, and said unto him: ‘Draw thy sword, and kill me, that men say not of me: A woman slew him.’ And his young man thrust him through, and he died.
..In those days, being conquered at the hands of women was considered humiliating
Eliyahu Rabba, Chapter 9
Devorah's husband was unlearned (am ha'aretz). She said to him, "Let me make you wicks and you'll take them to the Tabernacle in Shilo; your portion will be among righteous people there and you'll merit the World to Come. He made thick wicks to increase their light, and that's why his name was Lapidot ("torches"). And God said to Devorah, "You both intended to light up the Tabernacle; I, too, will make your light shine in Israel and Judah, and among all the 12 tribes."
Tanna D'vei Eliyahu 9
Since Barak trusted God and believed in Devorah's prophecy, as it says, "If you come with me I will go, but if you don't come with me I will not go," he therefore shared in the song with her, as it says, "And Devorah and Barak sang…"
Midrash – Yalkut Shimoni, Judges 43
Sisera came to fight them with 40,000 officers, who each led 100,000 soldiers. There was no city that didn't collapse from the force of his battle cry, and even an animal in the field could be immobilized by his voice.
(2) When attacks came upon Israel and then the nation repented voluntarily, may God's Name be blessed.
(ד) יי בצאתך משעיר . זה מתן תורה , כמה שנאמר ( דברים לג ב ) וזרח משעיר למו , ומה עניינה לכאן , כך אמרה דבורה : קשה היא התורה לפרוש ממנה וטובה היא לדבק בה , שהרי במורא ובגבורה נתנה , ולכך נמסרו ישראל ביד אויביהם על פרישתם הימנה וכשהתנדבו לעסוק בה נושעו , כל זה יש ללמוד מתרגומו של יונתן :
"God, as You left Seir" – this is the Giving of the Torah… What is this [story] doing here? Devorah said, "Torah is difficult to stray away from and good to attach oneself to… This why the Jewish people are given to their enemies when they leave it, and are saved as soon as they choose to immerse in it again.”
Talmud – Eruvin 54b
"The riders of white donkeys, sitting in judgment, and walking in the path, conversing" (Judges 5:10). “The riders of donkeys” – these are the scholars, who would go from city to city and from state to state to teach Torah. “White donkeys” – they would make the Torah clear as day. “Sitting in judgment” – judging truth. “Walking” – scholars of the written text. “On the path” – scholars of the Oral Law. “Conversing” – scholars of Talmud, whose conversations are all Torah.