Ramayana
निवातकवचास्तत्र दैत्या लब्धवरा वसन् । राक्षसान्तान्समागम्य युद्धाय समुपाह्वयत् ॥ 7-23-6 ॥
There dwelt the Daityas called Nivatakavachas, who had obtained a boon; and approaching those Rakshasas, he summoned them to battle.
english translation