Valmiki Ramayana Yuddha Kanda Sarga 73 Shloka 70
Original Shlokaमन्येस्वयम्भुर्भगवानच्नित्योयस्यैतदस्त्रंप्रभवश्चयोऽस्य । बाणावपातास्त्वमिहाद्यधीमन्मयासहाव्यग्रमनास्सहस्व ।।6.73.70।।
1 source checked for this shloka
एतत् this, अस्त्रम् weapon, यस्य his, यः that which, अस्य whose, प्रभवः glorious, भगवान् god, स्वयम्भुः creator, अच्नित्यः inconceivable, मन्ये remain calm, धीमन् wise, त्वम् you, इह here, अद्य now, अव्यग्रमनाः undisturbed, बाणावपातम् hail of arrows, मयासह with me, सहस्व tolerate.
"This weapon of him (Indrajith) is that of the glorious creator and is presided by Him. By that reason he is inconceivable. O! Wise Lakshmana, remain calm and undisturbed at this hail of arrows."