"But Reuben heard it, and he delivered him out of their hands, and said, 'Let us not kill him.' And Reuben said to them, 'Shed no blood, but cast him into this pit which is in the wilderness, and do not lay a hand on him'--that he might deliver him out of their hands and bring him back to his father. So it came to pass, when Joseph had come to his brothers, that they stripped Joseph of his tunic, the tunic of many colors that was on him. Then they took him and cast him into a pit. And the pit was empty; there was no water in it" (Gen. 37:21-24).
It is good that Reuben dissuaded them from murder, but he should have taken a stronger stand while he had the opportunity. He compromises with his brothers while hoping to figure out a way to release the boy, but this plan will never come to fruition.
"And they sat down to eat a meal. Then they lifted their eyes and looked, and there was a company of Ishmaelites, coming from Gilead with their camels, bearing spices, balm, and myrhh, on their way to carry them down to Egypt. So Judah said to his brothers, 'What profit is there if we kill our brother and conceal his blood? Come and let us sell him to the Ishmaelites, and let not our hand be upon him, for he is our brother and our flesh.' And his brothers listened" (Gen. 37:25-27). Instead of killing Joseph immediately, they threw him into a pit and considered their next move. A traveling caravan provided an enticing option: Sell their brother as a slave! This would benefit them financially and would prevent them from committing murder. This seemed like the best way to get Joseph out of their life once and for all (or so they thought!). No more would they have to listen to his dreams! While Reuben was not present, they sold Joseph for twenty pieces of silver. This was the average purchase price of a boy Joseph's age (cf. Lev. 27:5)
"Then Reuben returned to the pit, and indeed Joseph was not in the pit; and he tore his clothes. And he returned to his brothers and said, 'The lad is no more; and I, where shall I go?' So they took Joseph's tunic, killed a kid of the goats, and dipped the tunic in the blood. Then they sent the tunic of many colors, and they brought it to their father and said, 'We have found this. Do you know whether it is your son's tunic or not?' And he recognized it and said, 'It is my son's tunic. A wild beast has devoured him. Without a doubt Joseph is torn to pieces.' Then Jacob tore his clothes, put sackcloth on his waist, and mourned for his son for many days. And all his sons and all his daughters arose to comfort him; but he refused to be comforted, and he said, 'For I shall go down into the grave to my son in mourning.' Thus his father wept for him" (Gen. 37:29-35).
Reuben is distraught after learning that Joseph was gone. He, as the firstborn, doesn't know how he's going to account for Joseph's absence to his father. His brothers have a plan: Pretend Joseph was killed by a wild animal. They still had his special tunic, so they used animal blood to make it look like Joseph had been torn to pieces. Israel did not suspect any foul play on the part of his sons. He immediately goes into mourning and would not cease. Joseph's "death" caused Jacob immense suffering and grief. It's as if he will die in sorrow over his son. No doubt this was a difficult burden for the brothers to bear--to see their father in so much pain (day after day) and to secretly know that they had caused it. As a side note, it is easy to see here that emotions are not an adequate guide for human conduct because they are often wrong. Israel has no doubt that Joseph is dead, yet he is mistaken and would eventually be reunited with his favored son. Emotions, no matter how strong they may be, can be mistaken.
"Now the Midianites had sold [Joseph] in Egypt to Potiphar, an officer of Pharaoh and captain of the guard" (Gen. 37:36).