It's been a while since I've seen this phrase--I like it. I first heard it...let me look...geeze time is weird and relative--it feels like two or three years ago but it was not quite 13 months ago that Maria Rattray quoted a Franciscan friar for, “Where we are betwixt and between the familiar and the completely unknown. There alone is our old world left behind, while we are not yet sure of the new existence. That’s a good space where genuine newness can begin. Get there often and stay as long as you can by whatever means possible…This is the sacred space where the old world is able to fall apart, and a bigger world is revealed.” See Maria's https://medium.com/illumination/our-very-lives-are-peppered-with-liminal-spaces-spaces-between-our-yesterdays-and-a-future-we-know-22f13a68be0 and the poem of mine that her essay partially inspired, https://marcus17043.medium.com/open-the-windows-to-your-soul-5db331a8870f, which has 11 short stanzas and concludes with:

Cross the door’s threshold

Enter the liminal space

Alchemy awaits

Trust metamorphic process

From chrysalis shall emerge