Valmiki Ramayana Ayodhya Kanda Sarga 19 Shloka 33
Original Shlokaन वनं गन्तुकामस्य त्यजतश्च वसुन्धराम्। सर्वलोकातिगस्येव लक्ष्यते चित्तविक्रिया।।2.19.33।।
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वनम् to the forest, गन्तुकामस्य having determined to go, वसुन्धराम् the earth, त्यजतश्च renouncing, सर्वलोकातिगस्येव who is beyond all worldly affairs, चित्तविक्रिया change of mind, नलक्ष्यते could not to be seen.
Rama was determined to renounce the kingdom and go to the forest. So none could see any change in his mind. (For) he was one beyond all worldly affairs.