Atharvaveda 6.49.2

6.49.2

meṣá iva vái sáṃ ca ví corv àcyase yád uttaradrā́v úparaś ca khā́dataḥ |
śīrṣṇā́ śíró 'psasā́pso ardáyann aṃśū́n babhasti háritebhir āsábhiḥ ||2||

Like a ram, thou art bent both together and wide apart, when in the upper wood [the upper] and the lower stone devour; exciting (ard) head with head, breast (ápsas) with breast, he gnaws the soma-stalks (aṅçu) with green mouths.