“Mahabharata war happened between the Pandavas and the Kauravas in 3139 BC or 5152 years before, from this year 2013 AD. The Pandavas, after winning the Mahabharata war, ruled Hastinapur for 36 years and 8 months until the beginning of Kaliyug in 3102 BC. In the end of the Mahabharata war when Duryodhana was killed by Bheema, then remaining Kauravas warriors (including Ashwathama) made a deadly attempt to kill the Pandavas brothers in the night when they would be sleeping. Ashwathama was the son of Dronacharya, Guru of Pandavas and the Kauravas.
On that night Lord Krishna somehow took all the 5 Pandavas, somewhere else & Ashwathama entered into the tent of the Pandavas and mistakenly killed all the 5 sleeping sons of Pandavas and set the camp on fire. Later on Ashwathama through deadly weapon called Brahmastra also killed the child in the womb of the pregnant ‘Uttara’ (wife of martyr Abhimanyu - the great archer and son of Arjuna), however Lord Krishna later revived the child through His Grace. So Ashwathama tried to kill everyone in the Pandava’s family. On this Lord Krishna became very angry with Ashwathama & Cursed him badly. Lord Krishna Cursed him like this:
O! Ashwathama “You will carry the burden of all the people’s sins on your shoulders and will roam alone like a ghost without getting any love and courtesy till the end of Kaliyuga, You will have neither any hospitality nor any accommodation; You will be in total isolation from the mankind and society; Your body will suffer from a host of incurable diseases forming sores and ulcers that would never heal. May you, Ashwathama, lead the most wretched life anyone can ever lead. May you never receive love or affection ever in your life unto the end of Time ”.
Ashwathama had a Mani (gem) since his birth in his forehead which used to protect him from the fear of any snakes, ghosts, demigods and demons. Lord Sri Krishna asked Ashwatthama to surrender this Mani (gem) & took it from him. Lord Sri Krishna further said that “the wound caused by the removal of this Mani (gem) on his forehead will never heal and he will suffer from leprosy and wound in his forehead will always seep blood and Puss, thus arousing a foul smell till the end of Kaliyuga”. So in this way, Ashwathama will be in search of death every moment, and yet he will never die. At the end of Kali Yuga, Ashwathama shall meet God Sri Kalki, the tenth avatar of Lord Vishnu.”
It is said that from the last 5152 years, Ashwathama is still roaming on earth in and around the Narmada river in India. As Mahakaal (Lord Shiva) can only free him from the curse so it is said that he still visits the shivling at a temple near the Narmada river every morning and places a rose flower there in temple which he creates from his tap / spiritual power every day.
So from the above story it is quite evident that we should never do any harm to anyone, as otherwise, God shall punish us badly. In Bhagwat Gita Lord Krishna says that:
patanti narake ’suchau" (Bhagwat Gita: Chapter Sixteen verse 16)
"Sri Krishna said: O Arjuna, Thus perplexed by various anxieties and bound by a network of illusions, these evil people become too strongly attached to sense enjoyment and fall down into hell."
"tan aham dvisatah kruran
ksipamy ajasram asubhan
asurisv eva yonisu" (Bhagwat Gita: Chapter Sixteen verse 19)
"Sri Krishna said: O Arjuna, "These haters, evil, cruel, & vilest among men, I ( God) repeatedly throw them into demoniacal wombs in this world."
"asurim yonim apanna
mudha janmani janmani
mam aprapyaiva kaunteya
tato yanty adhamam gatim" (Bhagwat Gita: Chapter Sixteen verse 20)
"Sri Krishna said: O Arjuna, Attaining repeated birth amongst the species of demoniac life, such persons can never approach Me. Gradually they sink down to the most abominable, lowest type of existence."
So let’s do good karmas only & not harm anybody by our acts. God shall be with us if we live a life doing good karmas / acts in our life. God shall bestow on us all the health, wealth, happiness & bliss of life, if our Karmas / acts are good.