Genesis 37:2
These are the generations of Jacob. Joseph, being seventeen years old, was feeding the flock with his brethren; and the lad was with the sons of Bilhah, and with the sons of Zilpah, his father’s wives: and Joseph brought unto his father their evil report.
At seventeen years old Joseph was still young when God chose him to do a special work for His people. Already his character was marked by purity, obedience to God, gentleness, fidelity, and truthfulness, the same qualities later seen in Egypt. This came from obedience to his father's righteous teaching and devotion to doing what was right. He was especially attached to his father, and his father loved him more than his other children.
He was troubled and grieved by his brothers' wrongdoing, and gently and meekly urged them to stop their wicked acts and turn from them. He then brought their conduct to his father in the hope that they would reform through his father's authority.
His report made his father aware of their evil conduct. His brothers were ashamed, enraged, and resentful that their sin had been exposed, though they hid their feelings. Their envy over their father's love for Joseph grew more bitter into hatred and a desire to kill and murder him.