The king wants the sacred cups from the Jerusalem Temple (Dan 5:2-5:2)

“Under the influence

Of the wine,

King Belshazzar

Commanded

That they bring

In the vessels

Of gold,

The vessels

Of silver,

That his father,

King Nebuchadnezzar,

Had taken out

Of the temple

In Jerusalem.

Thus,

The king,

His lords,

His wives,

His concubines,

Might drink

From them.”

This King Belshazzar commanded his servants to bring the sacred gold and silver vessels that King Nebuchadnezzar had taken from the Temple in Jerusalem. Here the author calls Nebuchadnezzar his father, but he was his grandfather. Thus, the king, these invited lords, his wives, and his concubines might drink wine from these sacred silver and gold cups. I am not sure if there were that many sacred vessels to accommodate a 1,000 people.