Canto 2 -
Ayodhyā-kāṇḍa
Chapter 78: Śatrughna Punishes Mantharā
Text 2.78.19

स बली बलवत्क्रोधाद्गृहीत्वा पुरुषर्षभः।
कैकेयीमभिनिर्भर्त्स्य बभाषे परुषं वचः॥

sa balī balavat-krodhād gṛhītvā puruṣa-rṣabhaḥ
kaikeyīm abhinirbhartsya babhāṣe paruṣaṁ vacaḥ

saḥ = that; balī = strong; balavat-krodhāt = in extreme anger; gṛhītvā = held [Mantharā]; puruṣa-ṛṣabhaḥ = prince; kaikeyīm = Kaikeyī; abhinirbhartsya = and severely criticized; babhāṣe = He spoke; paruṣam = harsh; vacaḥ = words.

That strong prince held [Mantharā] and severely criticized Kaikeyī in extreme anger. He spoke harsh words.

It is inferred from Śatrughna’s severe criticism of Kaikeyī that Kaikeyī had beseeched [Him] to release Mantharā.1

1 Śatrughna was angry with Mantharā. Why did He severely criticize Kaikeyī, a third party? Because she approached Him and requested that He let Mantharā go.