Knittle Ho Need Some Help, Part II

The good news is that I have finished the body of the Irish cable bag. I tried to take some pictures of it, but someone was being so helpful that he obscured the shots:

Hey, what's this?

Mmm, looks yummy. Bet it tastes like chicken.

It feels nice on my little toes, too. It makes me feel pensive.

Yes, this is perfect. It is clearly intended for me.

All right, enough of that silliness, and thank you for indulging me. Now on to the real stuff. Here's how the bag looks (other side, happily, looks exactly the same):

Making the bobbles was an adventure. And here is what I've still got on the needles--40-some odd stitches just dying to be bound off.

And here's the problem--the recipe won't let me just bind off, it has special instructions that I simply cannot understand. I know you have the book (page 71, if you're interested), but I'll rewrite the instructions here:

Top edge, second side:

Work I-cord edge as follows: Cable CO 3 sts. *K2, ssk (1 st from cord and 1 st from bag), slip 3 sts back to left needle; repeat from * until all sts of top edge are joined to I-cord and only 3 sts of I-cord remain.

Now, let's dissect the particularly confusing bits, shall we??

Cable CO 3 sts: Okay, I can do this, but what am I casting on to? The same needles that I've been using for the bag body?

ssk (1 st from cord and 1 st from bag): Oh, dear. This one really has me stymied. "1 st from cord?" What cord? Is this related to the cable CO? How can I have stitches from 2 different places, when all I have in front of me is the bag body??

slip 3 sts back to left needle: When I tried to cast on and then do the ssk on the same needles that the bag body is on, I ended up with only two sts. So obviously I'm doing something wrong.

Obi-wan-knitobi, can you help??