I've googled extensively but couldn't find the answer; nor could I find it in my own books.
It's possible, though, that it might have been commissioned by Philip the Handsome, Duke of Burgundy, who did order "an altarpiece, 9 feet high and 11 feet wide, depicting scenes of the Last judgment, heaven and hell. This painting has never been found. But the commission makes it clear that Bosch was regarded as a master painter of great respectability and deep religious faith."
Bosch was born the duchy of Brabant, which was then the realm of the dukes of Burgundy.
So it could have been Philip the Handsome.