Valmiki Ramayana Sundara Kanda Sarga 52 Shloka 21

राजन् O king, अपि च and even so, अस्मिन् when he, हते is killed, यः whoever, महोदधेः ocean, परं पारम् to the other side, पुनः again, इह here, आगच्छेत् who can come, अन्यम् other, खेचरम् who can come through sky and reach, न पश्यामि I do not see.

"O king If he is killed, I do not see any one who can cross this great ocean and come by air to reach this place.