I don't have a pattern for it because I made it up. But I can give you a basic idea of how I made it.
*I made it by feel, so I can't guarantee that this will work for you without some tweaking, especially for the measurements and number of cast on stitches. I strongly recommend that you knit up a swatch or two before blindly following these directions. In essence, you want to knit up a cabled panel the size of the front of your pillow with 2 long flaps that wrap around and overlap in the back.
It's knit in one big long rectangle, about 40 inches by 15 inches, and it fits on a standard 15x15 throw pillow. The first and last 11 inches are done in a p2k2 rib with an extra purl stitch at each end followed by a 2 stitch garter strip for easy seaming.
I used size 10 needles and lions brand wool ease thick & quick.
Back flap number one (back of pillow)
Cast on. I did 52 stitches.
First row is k2, p3; [k2, p2] to last 7 stitches, k2, p3, k2.
Second row: k5, [p2, k2] to last 7 stitches, p2, k5. Continue in that pattern for 11 inches.
Cable panel (front of pillow)
The cable pattern is from the Encyclopedia of Knitting and you can view it here
. It's called "Smocked Cable". If the link takes you to the index, hit "previous" and you should go right to the pattern.
You'll want to start on the right side with either row 6 or 12. And you'll be keeping a border or 2 reverse stockinette stitches plus 2 garter stitches on either side of the cable panel.
Continue with the cable pattern until you've knit up about 14-15 inches, ending on row 6 or 12.
Back flap number 2 (back of pillow)
Then go back to the same k2,p2 rib that you used for the first 11 inches of the work. Bind it off. Wrap it around the throw pillow like a envelope. Pin it and stitch together the edges.
I hope that helps. If you have any other questions, let me know.