This is a knit-on insert/panel. It is worked over a multiple of 3 + 2 stitches.
Stitch Substitutions:
~~~~~~~~~~~~~~~~~~
M1Lp = Purl 1 st, turn.
p1 tbl = P2tog, turn.
w&t = turn
Rows 31-36 can be repeated until the desired height is reached.
Repeat rows 41-46 as needed for length (repeat [ ] as many times as needed).
Repeat rows 61-66, 71-76 until only 26 stitches remain (repeat [ ] as many times as needed).
Knits on to a multiple of 3 + 1 sts.
Shown with a cast-on count of 2 stitches.