When a baby horse is born, it is said to be by its sire and out of its dam.
As in, Secretariat was by Bold Ruler, out of Somethingroyal.
In other words, the father authors the foal, the mother simply expels it.
This strikes me as a little sexist.
But it also reminds me of that timeworn writing trope wherein the author claims to be the mere vessel for some kind of divine authorial force.* You know what I'm talking about: "The words seemed to write themselves," "This character came out of nowhere and all I could do was sit back for the ride," et cetera.
In this context the writer becomes mare, and the muse the stallion.
Which is at least a satisfying switch of their classic gender assignments.
*a.k.a. "the Muse." I detest "the Muse."