Reuven's 'Regret' of the sale

(28) When Midianite traders passed by, they pulled Joseph up out of the pit. They sold Joseph for twenty pieces of silver to the Ishmaelites, who brought Joseph to Egypt. (29) When Reuben returned to the pit and saw that Joseph was not in the pit, he rent his clothes. (30) Returning to his brothers, he said, “The boy is gone! Now, what am I to do?”

(1) וישב ראובן AND REUBEN RETURNED — When he (Joseph) was sold he had not been present, for it was his day (his turn) to go to attend to his father (Genesis Rabbah 84:19)

(1) וישב ראובן אל הבור, Reuben returned to the pit, etc. What was Reuben's argument when he complained to the brothers ואני אנה אני בא, "where shall I go?" Would Joseph not have been lost even if his own suggestion to throw him into a pit had been carried out? After all, the Torah itself testified that Reuben had never told his brothers that he intended to save Joseph and to restore him to his father! When Yehudah said to the other brothers: "what profit is there in killing our brother, etc," does this not prove that Joseph's remaining in the pit was meant to result in his death? How then could Reuben complain to his brothers? (2) Actually, Reuben argued that inasmuch as he was the oldest, his father would charge him with leading the search for the missing Joseph from one end of the earth to the other. If Joseph had remained in the pit, he would have brought Joseph's remains to his father and explained to him that wild beasts had killed him. This would have been the end of his involvement. Now he could not do this. This is why he said: "where shall I go?" As a result the brothers hit on the idea of slaughtering a male goat and dipping Joseph's tunic in its blood, etc. By returning the tattered and blood-soaked remains of Joseph's striped coat they made it unnecessary for Reuben to start a search for Joseph.

(1) וישב, he returned from wherever he had gone to his brothers, going back to the pit to see if he could rescue Joseph without his brothers finding out, and to return him to his father.

(1) וישב ראובן AND REUBEN RETURNED Another explanation is: he had not sat with them at the meal because he was occupied with his sack-cloth and fast in penitence for having disturbed his father’s couch (Genesis Rabbah 84:19).

(1) ואני אנה אני בא, “as for me in what terrible situation have I gotten myself into?” Why was Reuven more concerned and afraid than the other brothers? On the contrary, the brother who should have been the one most afraid was Yehudah, who had acted as the brothers’ leader until that time! We must therefore say that he was more concerned because his father had treated Joseph as his firstborn, and he, his father’s biological firstborn could have been accused as being negligent in looking after him due to feelings of jealousy. In addition, he had already been guilty of an indiscretion in Bilhah’s bedroom, which had shown his father that he felt aggrieved about his father having favoured Rachel and her children. Rashi already commented concerning the tales Joseph had been telling to his father, all putting the sons of Leah in a bad light.