Canto 3 -
Araṇya-kāṇḍa
Chapter 28: Śrī Rāma Attacks Khara
Text 3.28.12

हन्तारं सर्वसैन्यस्य पौरुषे पर्यवस्थितम्।
परिश्रान्तं महासत्त्वं मेने रामं खरस्तदा॥

hantāraṁ sarva-sainyasya pauruṣe paryavasthitam
pariśrāntaṁ mahā-sattvaṁ mene rāmaṁ kharas tadā

hantāram = and had destroyed; sarva-sainyasya = his entire army; pauruṣe = in manliness; paryavasthitam = well established; pariśrāntam = He was tired; mahā-sattvam = [though] was greatly powerful; mene = thought that; rāmam = Rāma; kharaḥ tadā = Khara.

[Though] Rāma was greatly powerful, well established in manliness and had destroyed his entire army, Khara thought that He was tired.

GLOSS. This is an indication that [Khara] was mistaken.

NOTE. Prabhupāda explains such misconceptions demon harbor in his purport to Bhagavad-gītā 4.5 as follows:

Although Arjuna is a devotee of the Lord, he sometimes forgets the nature of the Lord, but by the divine grace a devotee can at once understand the infallible condition of the Lord, whereas a nondevotee or a demon cannot understand this transcendental nature. Consequently these descriptions in the Gītā cannot be understood by demonic brains... We may also note herein that a living entity forgets everything due to his change of body, but the Lord remembers because He does not change His sac-cid-ānanda body. He is advaita, which means there is no distinction between His body and Himself. Everything in relation to Him is spirit—whereas the conditioned soul is different from his material body. And because the Lord’s body and self are identical, His position is always different from that of the ordinary living entity, even when He descends to the material platform. The demons cannot adjust themselves to this transcendental nature of the Lord . . .