Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 19: Viśvāmitra Requests Daśaratha to Give Rāma
Text 1.19.4
अहं नियममातिष्ठे सिद्ध्यर्थं पुरुषर्षभ।
तस्य विघ्नकरौ द्वौ तु राक्षसौ कामरूपिणौ॥
ahaṁ niyamam ātiṣṭhe siddhy-arthaṁ puruṣa-rṣabha
tasya vighnakarau dvau tu rākṣasau kāma-rūpiṇau
aham = I; niyamam ātiṣṭhe = have taken initiation into a sacrificial performance; siddhi-artham = to attain certain spiritual results; puruṣa-ṛṣabha = O king; tasya = that performance; vighnakarau = obstruct; dvau tu = two; rākṣasau = rākṣasas; kāma-rūpiṇau = who can change forms at will.
O king, I have taken initiation into a sacrificial performance to attain certain spiritual results. Two rākṣasas who can change forms at will obstruct that performance.
This describes what he has in his mind.