Valmiki Ramayana Ayodhya Kanda Sarga 118 Shloka 8

पुरा formerly, पाणिप्रदानकाले च at the time of bestowal of my hand to Rama, अग्नि सन्निधौ in the presence of sacrificial marriage fire, जनन्या by my mother, यत् वाक्यम् that word, अनुशिष्टा आस्मि I have been taught, तदपि that also, मे to me, धृतम् hold

When I have been taught by my mother earlier, at the time of bestowal of my hand to Rama in the presence of the sacrificial fire (as witness) is etched in my mind.