Valmiki Ramayana Aranya Kanda Sarga 37 Shloka 15

शरार्चिषम् arrows are flames, अनाधृष्यम् cannot be overpowered, चापखड्गेन्धनम् bow and sword as fuel, रणे in war, दीप्तम् blazing, रामाग्निम् fire of Rama, सहसा at once, प्रवेष्टुम् to enter, त्वम् you, न अर्हसि should not.

You should not enter into the unquenchable fire that is Rama, the fire that has the arrows (of Rama) as its flames and his sword and bow as fuel.