Atharvaveda 8.4.20

8.4.20

etá u tyé patayanti śváyātava índraṃ dipsanti dipsávó 'dābhyam |
śíśīte śakráḥ píśunebhyo vadháṃ nunáṃ sr̥jad aśániṃ yātumádbhyaḥ ||20||

Here fly these dog-sorcerers (çváyātu); Indra the unharmable they the harm-seeking seek to harm; the mighty one (çakrá) sharpens his deadly weapon for the treacherous ones (píçuna); now may he let fly (sṛj) the thunderbolt at the sorcerers (yātumánt).