Atharvaveda 5.3.11

5.3.11

arvā́ñcam índram amúto havāmahe yó gojíd dhanajíd aśvajíd yáḥ |
imáṃ no yajñáṃ vihavé śr̥ṇotv asmā́kam abhūr haryaśva medī́ ||11||

Hitherward do we call Indra from yonder, who is kine-conquering, riches-conquering, who is horse-conquering; let him hear this sacrifice of ours at our separate call; of us, O thou of the bay horses, hast thou been the ally (medín).