Valmiki Ramayana Bala Kanda Sarga 77 Shloka 30
Original Shlokaतस्याश्च भर्ता द्विगुणं हृदये परिवर्तते। अन्तर्जातमपि व्यक्तमाख्याति हृदयं हृदा।।1.77.30।।
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भर्ता her husband Rama, तस्या: her, हृदये heart, द्विगुणम् twice, परिवर्तते revolving, हृदयम् in heart, अन्तर्जातम् अपि every thought born inside also, हृदा with heart, व्यक्तम् clearly, आख्याति he will communicate.
For sita her husband was doubly dear. They were clearly communicating through each other's heart every thought generated in the mind.