Rejoice - at our calamities (Psa 137:7). This is a prophecy that Edom should exult over the fall of Jerusalem. At the same time it is implied, Edom’s joy shall be short-lived. Ironically she is told, Rejoice while thou mayest (Ecc 11:9).
cup - for this image of the confounding effects of God’s wrath, see Jer 13:12; Jer 25:15, Jer 25:16, Jer 25:21; as to Edom, Jer 49:7-22.