rāma rāma mahā-bāho
na jāne tava vikramam
yasyaikāḿśena vidhṛtā
jagatī jagataḥ pate
rama rama -- O Rama, Rama; maha-baho -- O mighty-armed one; na jane -- I do not appreciate; tava -- Your; vikramam -- prowess; yasya -- whose; eka -- one; amsena -- by a portion; vidhrita -- is sustained; jagati -- the earth; jagatah -- of the universe; pate -- O master.
The phrase ekamsena ("with a single portion") refers to the Lord's expansion as Sesha. This is confirmed by the acaryas.