Meaning of "delight the heart of a wheelbarrow"

I found this sentence in The Green Fool by Patrick Kavanagh:

I heard phrases of whimsical prophecy and exciting twists of language that would delight the heart of a wheelbarrow or a modernist poet

I'm not sure what this means. Why delighting the heart of a wheelbarrow?

To offer a more prosaic answer :-), heart of a wheelbarrow is basically a slang or colourful way of saying hard-hearted or humourless. It's quite a common phrase in Ireland - Kavanagh didn't invent it. I don't know if it's common elsewhere, and Google is uncooperative in providing supporting evidence. As @HotLicks has pointed out, it stems from the fact that a wheelbarrow is hollow and has no heart.

What Kavanagh means by delight the heart of a wheelbarrow in this context is something like:

extract a smile from a hard-hearted or humourless person

A more common variant is break the heart of a wheelbarrow, which can sometimes mean causes extreme sadness but more often means causes extreme frustration. For example:

trying to get around the city during rush-hour traffic would break the heart of a wheelbarrow