Sl1 help from baby hat pattern

I have a question about this baby hat pattern
it says on row 4 and beyond
Row 4: k2, yo, k3, sl1, k2tog, psso, k3, yo, k1; rep from, end k2 instead of k1
I want to know sl1 in this pattern is it knit wise or purl wise?:think:
Please help! :heart:

When a slip stitch is part of a decrease you slip it knit wise.