upasrjya tamas tivram
jaharasvam punar harih
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
My dear Vidura, Indra, being the King of heaven and very powerful, immediately brought a dense darkness upon the sacrificial arena. Covering the whole scene in this way, he again took away the horse, which was chained with golden shackles near the wooden instrument where animals were sacrificed.