This parable is from Shrimad Bhagwat Purana. We should take help from the Eternal Energy for it gives us strength to forgive all deeds done to us and even forget them. God has given us free will to access everything. But, if we surrender the free will and let the Divine will function, we will be liberated.
Once there lived an old lady with her son. Some misunderstandings rose between mother and son. The son left home. Several weeks passed, and mother began losing her health. She soon appeared on the death bed.
She struggled with her body for several weeks. A saint visited the lady and said that she didn’t appear attached to her son. A saint could not decipher the reason behind the struggle. The lady should have left the body earlier as she was a pure soul. Suddenly, the saint realized that her son had not forgiven her for the cause.
The saint rushed to her son and conveyed about his mother. The son was obstinate. The saint asked him to forgive her mother, and she was struggling on her death bed. The boy replied that he had no capabilities to forgive her; God could forgive her. The saint lashed at the boy and said that God could not forgive her until he forgave his mother. The boy realized his mistake and rushed towards his mother.
He bowed before his mother, asked for forgiveness, and even forgave her. As the boy said the words, a ball of light rose from the body and merged with the divine oneness.
The lady would have died even if the son had not returned. But, the boy would have suffered for several lives. Thus, it is inevitable to forgive and forget.