BT Šab 65b(4) :מיטרא במערבא סהדא רבה פרת‏ : the Euphrates is the great witness to rain in the west
See the entire entry for sāheḏ/sāhīḏ, sāhḏā n.m. witness

BT Šab 65b(4) :מיטרא במערבא סהדא רבה פרת‏ : the Euphrates is the great witness to rain in the west
See the entire entry for prā/aṯ n.m. The Euphrates