I wish I could find an original source for this quote, but unfortunately I haven’t been able to. I’m 100% sure that this does not come from any Buddhist scripture, but is of very recent vintage.
I’ve found it in a couple of books, but the oldest of these is a self-published work called “Inspiration to Mankind,” by Bendalam Krishna Rao . This book is a collection of quotes attributed to the Buddha — many of them fake. There is no publication date in the book itself, but based on information in Google Books and Archive.org I believe it was published in 2014.
It’s all over the web. The earliest instance I’ve found so far is from approximately 2009, on a Yahoo Questions page where it’s not attributed to the Buddha but is simply described as a “proverb.”
If you find any earlier references, please let me know.
So at the moment I’ve no idea where this quote is from, who wrote it, or how it became attributed to the Buddha. The only thing I’m confident of is that the Buddha never said it.
The Buddha was a fan of silence. He said to his monks that when they gathered they should either talk about Dhamma (the teachings) or remain silent.
A particularly nice quote from the Sutta Nipata discusses how it’s the wise that are silent, while the foolish talk much:
Know this from waters’ flow—
those by rocks and pools—
such rills and becks gush noisily,
great waterways flow quiet.
What is unfilled makes noise
but silent is what’s full,
the fool is like the pot half-filled,
the wise one’s like a lake that’s full.
There’s much mention of space in the scriptures, largely because there is a meditative attainment called “the sphere of infinite space.” That’s not described as being the home of the awakened, however. In fact the Buddha found it unsatisfactory.