What do I do "twice"

Here is a “make bobble” pattern exactly as written:

K in (front, back, front, back) of same st, [sl 4 sts just made to LH needle, pull yarn tight behind work and k4] twice, pass the last 3 sts, one at a time, over the first st

My question is what exactly am I doing “twice”? I do the front-back-front-back, slip the 4 stiches from the right needle back to the left hand needle, knit these 4 stitches then what do I do?

It appears to me that you will be doing everything within the brackets twice. Once you’ve followed the bracketed instruction the first time, you will again have 4 stitches, now on your right needle. Just do the whole thing again - slip them to the left needle, pull yarn tight and knit all 4 stitches again. Then go on to pass the last 3 stitches, one at a time, over the first.