Canto 3 -
Araṇya-kāṇḍa
Chapter 9: Sītā Requests Rāma to Give up His Weapons
Text 3.9.21

नित्यं शस्त्रं परिवहन्क्रमेण स तपोधनः।
चकार रौद्रीं स्वां बुद्धिं त्यक्त्वा तपसि निश्चयम्॥

nityaṁ śastraṁ parivahan krameṇa sa tapo-dhanaḥ
cakāra raudrīṁ svāṁ buddhiṁ tyaktvā tapasi niścayam

nityam = always; śastram = the weapon; parivahan = by protecting; krameṇa = gradually; saḥ = he; tapaḥ-dhanaḥ = who was rich in austerity; cakāra = became; raudrīm = violent; svām buddhim = in attitude; tyaktvā = abandoned and; tapasi = to engage in austerity; niścayam = his determination.

By always protecting the weapon, he who was rich in austerity gradually abandoned his determination to engage in austerity and became violent in attitude.

Svām indicates that he developed the attitude unique to those who wield weapons.1

1 Rāmāyaṇa-bhūṣaṇa: svāṁ śastra-dhāry-asādhāraṇām.