Our Gemara discusses how to interpret the following verse in (Shemos 21:33-34):

וְכִֽי־יִפְתַּ֨ח אִ֜ישׁ בּ֗וֹר א֠וֹ כִּֽי־יִכְרֶ֥ה אִ֛ישׁ בֹּ֖ר וְלֹ֣א יְכַסֶּ֑נוּ וְנָֽפַל־שָׁ֥מָּה שּׁ֖וֹר א֥וֹ חֲמֽוֹר׃

If a man uncovers a pit, or if a man digs a pit, and does not cover it, and an ox or a donkey falls into it:

בַּ֤עַל הַבּוֹר֙ יְשַׁלֵּ֔ם כֶּ֖סֶף יָשִׁ֣יב לִבְעָלָ֑יו וְהַמֵּ֖ת יִֽהְיֶה־לּֽוֹ׃

The owner of the pit must pay. He must compensate its owner with money, and the dead [animal] remains his [its original owner’s] possession.

Be'er Mayim Chaim (Bamidbar 5:7) interprets this verse allegorically and ties it into Reuven's sin and repentance. The pit literally represents the pitfalls of sin, just as a person falls into a pit, they also fall into sin. Just as the pit is a hazard that remains in the landscape for others to stumble upon repeatedly until it is remedied, a person, when repenting, must correct the moral weakness and failing that led to the sin.

Bereishis (37:29) tells us that Reuven returned to the "pit," hoping to rescue Yosef but discovered that the brothers had already sold him. He cries out:

וַיָּ֤שָׁב רְאוּבֵן֙ אֶל־הַבּ֔וֹר וְהִנֵּ֥ה אֵין־יוֹסֵ֖ף בַּבּ֑וֹר וַיִּקְרַ֖ע אֶת־בְּגָדָֽיו׃

Reuven returned to the pit, but behold, Yosef was not in the pit. He [then] tore his clothes [in grief].

The Midrash (Yalkut Trey Asar 516):

וישב ראובן אל הבור רבי ברכיה אומר אמר לו הקב"ה אתה פתחת בתשובה תחילה חייך שבן בנך בא ופותח בתשובה תחילה שנאמר (הושע י"ד, ב') שובה ישראל

Reuven returned to the pit, and Rabbi Berechia said: The Holy One, blessed be He, said to him, "You began with repentance first, by your life, your son's son shall come and begin with repentance first," as it is said (Hosea 14:2), "Return, O Israel."

Be'er Mayim Chaim asks, how is Reuven's repentance meritorious or even unique? First, the Midrashim record Adam as also repenting, and secondly, repentance is one of the 613 mitzvos. What made Reuven's repentance so special?

Be'er Mayim Chaim answers that Reuven had started fasting, mourning, and repenting for having interfered with his father's conjugal rights (see Tosafos Bava Kama 92a, "Mi," and Rashi on this verse.) However, his repentance was only complete when "He returned to the pit," which is when he saw the flaw in his character. The same arrogance and competitiveness that led him to overstep his bounds in relation to his father and mother's business was also the source of his jealousy of Yosef. So, imagine this: Reuven is wrapped up in prayer and self-flagellation. He returns and then finds out an even bigger catastrophe occurred. After he took all the actions of repentance, he merited the insight that allowed him to see why and how he sinned. He got hit in the face with the very same trap and pitfall.

When we seek to repent and change our ways, we must make efforts to uncover our original blind spot and defect; otherwise, history will repeat itself.