Shloka 3.44.15
मारीचवधः — The Slaying of Maricha (Golden Deer Deception)
शरीरं मृगरूपस्य विनिर्भिद्य शरोत्तमः।।।।मारीचस्यैव हृदयं बिभेदाशनिसन्निभः।
śarīraṃ mṛgarūpasya vinirbhidya śarottamaḥ | mārīcasyaiva hṛdayaṃ bibhedāśanisannibhaḥ ||
That excellent arrow, resembling a thunderbolt, pierced the body of the one in the form of a deer and tore apart the very heart of Mārīca.
The great arrow which was like a thunderbolt first pierced into the body of Maricha who had assumed the form of a deer and then tore his heart.
The arrow is described as 'śarottamaḥ' (excellent arrow) and 'aśanisannibhaḥ' (resembling a thunderbolt), indicating its unstoppable power and speed.
Maricha had assumed the deceptive form of a deer ('mṛgarūpasya') to lure Rama away from the hermitage.