Canto 3 -
Araṇya-kāṇḍa
Chapter 39: Mārīca Describes his Second Encounter with Lord Rāma
Text 3.39.16

अपि रामसहस्राणि भीतः पश्यामि रावण।
रामभूतमिदं सर्वमरण्यं प्रतिभाति मे॥

api rāma-sahasrāṇi bhītaḥ paśyāmi rāvaṇa
rāma-bhūtam idaṁ sarvam araṇyaṁ pratibhāti me

api = even; rāma-sahasrāṇi = thousands of Rāmas; bhītaḥ = in fear; paśyāmi = I see; rāvaṇa = O Rāvaṇa; rāma-bhūtam = to have become Rāma; idam = this; sarvam = entire; araṇyam = forest; pratibhāti = appears; me = to me.

In fear, I even see thousands of Rāmas! O Rāvaṇa, this entire forest appears to me to have become Rāma!

Mārīca saw Rāma not only by every tree, but he saw Him everywhere.

And this was not a delusion created by Śrī Rāmacandra. Mārīca notes this in his next verse.