Welcome to Knitting Help!
When the instructions say to "pattern" some number of stitches, it means to continue the stitches that you've have been using on previous rows so that the overall pattern continues. If your pattern has been ribbing (k1, p1)or stockinette stitch (knit one row, purl one row) then continue those stitches.
If you cast on 30sts, work 17sts and place the last 4sts from the right needle on a stitch holder, you should have 13sts remaining on the right needle and 13sts on the left needle. Work those 13sts on the left needle in the pattern stitch to the end of the row. (I don't understand where you have 9 stitches? On which needle?)
For the row with the cast on of 4 sts, those cast on stitches are placed over the space left by the 4sts that are on the stitch holder. So work 13sts in your pattern, cast on 4sts and continue knitting the row. You can use a backward loop cast on or a cable cast on
Good luck with the wrist warmers and come back with questions if you have more.