Tammuz
Tammuz is named once in the UPDV — as the foreign god whose women-mourners Ezekiel sees in vision at the very threshold of Yahweh's house, ranked by the chapter as one in a graded series of "great disgusting things" being practised inside the temple precincts.
The Vision at the North Gate
In the second of the four scenes Ezekiel is shown in the temple, the prophet is led from the altar court to the gate that opens northward and confronted there with a ritual that had taken root inside the sanctuary precincts: "Then he brought me to the door of the gate of Yahweh's house which was toward the north; and look, there sat the women weeping for Tammuz" (Eze 8:14). The location is exact — the gate of Yahweh's own house — and the offence is named without explanation. The women are seated, the act is ritual weeping, and the object of that weeping is Tammuz.
The framing on either side of the verse rates the rite within a series. The previous verse warns the prophet, "You will again see yet other great disgusting things which they do" (Eze 8:13), and the verse that follows reaches past the women's weeping toward something worse still — "Then he said to me, Have you seen [this], O Son of Man? You will again see yet greater disgusting things than these" (Eze 8:15). The mourning for Tammuz is therefore presented as a step in a climbing tour: a foreign rite practised at the gate of Yahweh's house, with worse to come.