Rasarnavasudhakara 3.96.p2

3.96.p2

ity antena hara-cāpa-dalanasya niṣiddhayā kartṛtayā anumantṛtayā stotṛtayā ca rāghava-viśvāmitra-pīrādi-parāmarśena brāhmaṇa-kṣatriyādi-varṇānāṃ saṅgrahaṇād varṇa-saṃhāraḥ |

— because social classes such as Brāhmaṇas and Kṣatriyas are gathered together through mention of Rāghava, Viśvāmitra, heroic individuals, and others, under the forbidden categories of being the agent, the approver, and the praiser of the breaking of Hara's bow, this is assembly of castes (varṇasaṃhāra).