Genesis 50:15
And when Joseph’s brethren saw that their father was dead, they said, Joseph will peradventure hate us, and will certainly requite us all the evil which we did unto him. And when Joseph’s brethren saw that their father was dead, they said, Joseph will peradventure hate us, and will certainly requite us all the evil which we did unto him.
After Jacob died, his sons became afraid that Joseph would now repay and punish them for all the evil they had done to him. They suspected he had only hidden his resentment and held back or postponed his revenge out of respect for their father while Jacob was alive. The memory of their own guilt made them fearful and distrustful, so that they could not trust Joseph's kindness toward them. The thought that he would now certainly take revenge filled them with distress. His answer to them in the verses that follow comforts them and makes clear that he does not seek revenge.