Canto 2 -
Ayodhyā-kāṇḍa
Chapter 74: Bharata Condemns Kaikeyī
Text 2.74.21
भयं कच्चिन्न चास्मासु कुतश्चिद्विद्यते महत्।
कुतोनिमित्तः शोकस्ते ब्रूहि सर्वहितैषिणि॥
bhayaṁ kaccin na cāsmāsu kutaścid vidyate mahat
kuto-nimittaḥ śokas te brūhi sarva-hitaiṣiṇi
bhayam = danger; kaccit na ca = there doesn’t seem; asmāsu = for us devas; kutaścit = from anyone; vidyate = to be; mahat = any great; kutaḥ-nimittaḥ śokaḥ te = [then] why are you in distress; brūhi = tell [me]; sarva-hita-eṣiṇi = O well-wisher of all.
O well-wisher of all, there doesn’t seem to be any great danger for us devas from anyone. [Then] why are you in distress? Tell [me].
It is implied that when the surabhi cow cries, it is mostly indicative of [such] a danger.