matur garbha-gato virah
sa tada bhrgu-nandana
dadarsa purusam kañcid
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O son of Bhrgu [Saunaka], when the child Pariksit, the great fighter, was in the womb of his mother, Uttara, and was suffering from the burning heat of the brahmastra [thrown by Asvatthama], he could observe the Supreme Lord coming to him.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Death generally involves remaining in trance for seven months. A living being, according to his own action, is allowed to enter into the womb of a mother by the vehicle of a father’s semen, and thus he develops his desired body. This is the law of birth in specific bodies according to one’s past actions. When he is awake from trance, he feels the inconvenience of being confined within the womb, and thus he wants to come out of it and sometimes fortunately prays to the Lord for such liberation. Maharaja Pariksit, while in the womb of his mother, was struck by the brahmastra released by Asvatthama, and he was feeling the burning heat. But because he was a devotee of the Lord, the Lord at once appeared Himself within the womb by His all-powerful energy, and the child could see that someone else had come to save him. Even in that helpless condition, the child Pariksit endured the unbearable temperature due to his being a great fighter by nature. And for this reason the word virah has been used.