Valmiki Ramayana Kishkindha Kanda Sarga 65 Shloka 15

मया by myself, पूर्वम् earlier, महाबलेश्चैव of Mahabali, यज्ञे in yagna, क्रममाणः the advancing Lord, विष्णुः Visnu, सनातनः eternal, त्रिविक्रमः Visnu of three strides, प्रदक्षिणीकृतः circumambulated.

'In the past, at the time of the wellknown yagna (of king Bali) I was very strong. I circumambulated the eternal Vishnu while he was taking three strides (in his incarnation of Trivikrama Vamana.)