Question: How Aśvattāmā released a second brahmāstra to kill Parīkṣit Mahārāja, when his first brahmāstra was fouled by Arjuna. As per my understanding from Mahābhārata, Aśvattāmā was only allowed to release brahmāstra only once since he did not know how to retract it after releasing.

Jayapatākā Swami: Aśvattāmā did not know how to withdraw the brahmāstra but he knew how to cast it. And somehow, I did not read anywhere that he can only send the brahmāstra once. It was not proper for him to release the brahmāstra if he did not know how to stop it....