Canto 2 -
Ayodhyā-kāṇḍa
Chapter 63: Daśaratha Remembering Killing a Sage’s Innocent Son
Text 2.63.25

ततोऽहं शरमुद्धृत्य दीप्तमाशीविषोपमम्।
शब्दं प्रति गजप्रेप्सुरभिलक्ष्य त्वपातयम्॥

tato ’haṁ śaram uddhṛtya dīptam āśī-viṣopamam
śabdaṁ prati gaja-prepsur abhilakṣya tv apātayam

tataḥ = then; aham = I; śaram = an arrow; uddhṛtya = took; dīptam = that was shining; āśī-viṣa-upamam = and equal to the poison of a venomous snake; śabdam prati = that sound; gaja-prepsuḥ = desirous of capturing that [wild] elephant; abhilakṣya tu = targeting; apātayam = I shot the arrow.

Then, I took an arrow that was shining and equal to the poison of a venomous snake. Targeting that sound I shot the arrow, desirous of capturing that [wild] elephant.

Gaja-prepsuḥ indicates that Dasaratha was desirous of killing that elephant. He targeted that sound while thinking that an elephant was close by.