Why would a seller specify "cash or hard money only"?

[Christopher Dru]

I'm reviewing some multifamily properties on the MLS and running the numbers for practice.

A seller of a triplex has the phrase "Cash or hard money only" in the property description.

Why would a seller accept only cash or hard money from a buyer? What is their incentive? If I have traditional financing from a bank, the seller gets paid nonetheless, so I'm trying to understand why they would only accept cash or hard money.

Any and all insight would be greatly appreciated. Thank you!