Given a string as input, generate a "blurred" version of that string.
Your input will be a single-line string of ASCII characters, containing a minimum of 2 alphanumeric characters
A string that is the "blurred" version of the input string.
A blurred string is one where every alphanumeric character from the original string has been paired with the ones adjacent to it, and each pair is separated by a space.
Any non-alphanumeric characters (whitespace, puncuation) in the input string must be ignored when determining adjacency of alphanumeric characters, and they must not included in the blurred string.
There must be no leading or trailing whitespace in the output string.
Ab bc cd
Blurry vision ->
Bl lu ur rr ry yv vi is si io on
We're #1! ->
We er re e1
I'm an example! ->
Im ma an ne ex xa am mp pl le
This is _not_ legible ->
Th hi is si is sn no ot tl le eg gi ib bl le
ab bc c5 5x
code-golf, so fewest bytes wins!