Canto 3 -
Araṇya-kāṇḍa
Chapter 6: The Sages Inform Rāma About the Rākṣasas Torturing Them
Text 3.6.23

पितुस्तु निर्देशकरः प्रविष्टोऽहमिदं वनम्।
भवतामर्थसिद्द्यर्थमागतोऽहं यदृच्छया॥

pitus tu nirdeśakaraḥ praviṣṭo ’ham idaṁ vanam
bhavatām artha-siddhy-artham āgato ’haṁ yadṛcchayā

pituḥ tu = of My father; nirdeśakaraḥ = to carry out the instruction; praviṣṭaḥ aham = having entered; idam = this; vanam = forest; bhavatām = your; artha-siddhi-artham = to fulfill purposes; āgataḥ = have come; aham = I; yadṛcchayā = by the ways of providence.

Having entered this forest to carry out the instruction of My father, I have come by the ways of providence to fulfill your purposes.

He implies that He has come to fulfill their purposes on the pretext of carrying out His father’s orders.