Valmiki Ramayana Sundara Kanda Sarga 58 Shloka 125
Original Shlokaतमक्षमागतं भग्नं निशम्य स दशाननः। तत इन्द्रजितं नाम द्वितीयं रावणस्सुतम्।।5.58.125।। व्यादिदेश सुसंकृद्धो बलिनम् युद्धदुर्मदम्।
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दशाननः tenfaced, सः रावणः that Ravana, आगतम् gone, अक्षम् of Aksha, भग्नम् destroyed, निशम्य after hearing, सुसंकृद्धः became very angry, ततः then, बलिनम् strong, युद्धदुर्मदम् thirsting for war, इन्द्रजितं नाम named Indrajit, द्वितीयम् second, सुतम् son, व्यादिदेश gave instruction.
"When Aksha was done to death, the tenfaced Ravana was enraged and gave instruction to the second son, called Indrajit who was thirsting for war.