Valmiki Ramayana Ayodhya Kanda Sarga 12 Shloka 66
Original Shlokaकैकेय्या क्लिश्यमानेन रामः प्रव्राजितो मया।।2.12.66।। यदि सत्यं ब्रवीम्येतत्तदसत्यं भविष्यति।
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कैकेय्या by Kaikeyi, क्लिश्यमानेन by being tortured, मया by me, रामः Rama, वनम् to the forest, प्रव्राजितः was sent, एतत् this, सत्यम् truth, ब्रवीमि यदि if I tell, तत् that, असत्यम् untruth, भविष्यति will become.
If I tell the truth 'Tortured by Kaikeyi, I have sent Rama to the forest', none will believe it and they will consider it untruth.