Srimad-Bhagavatam: Canto 1 - Chapter 1 - Verse 56

Sanskrit:

विमुच्य रशनाबद्धं बालहत्याहतप्रभम् ।तेजसा मणिना हीनं शिबिरान्निरयापयत् ॥ ५६ ॥

ITRANS:

vimucya raśanā-baddhaṁbāla-hatyā-hata-prabhamtejasā maṇinā hīnaṁśibirān nirayāpayat

Translation:

He [Aśvatthāmā] had already lost his bodily luster due to infanticide, and now, moreover, having lost the jewel from his head, he lost even more strength. Thus he was unbound and driven out of the camp.

Purport:

Thus being insulted, the humiliated Aśvatthāmā was simultaneously killed and not killed by the intelligence of Lord Kṛṣṇa and Arjuna.