Once the ripped seam is patched, tie off the thread with a knot by inserting the needle under the nearest stitch and pulling it until it forms a loop that's at least 1 inch wide. After you make the loop, insert the needle through the loop and pull it tight to create a knot (as seen in step 4).

Cut the thread connecting the newly formed knot and needle as close to the pillow stitch as possible, making sure to leave the knot in one piece to keep the seam secured.