Watching the video in slow motion (click on the gear), I see that after the left ping dai, the left arm makes two circles: arms open when he shifts back, left goes low, sword high, then the left threads inside the right so the sword is low and the left is high; then as the sword blocks up for the kick, and the left hand circles up to the right shoulder.
Fen Jiao – Master Tsao
The grab above is from the instructional video, which I highly recommend. Available from Taichihealthways.com.
Lesson 3 begins and ends facing into the back left corner. We begin from Du Li Shang Ci, stabbing up, and end with Gong Bu Xia Ci, stabbing down. The seven movements in this lesson are (numbering for the whole 49-step routine):
13. Pu bu chuan jian: To start, we are stabbing up with palm up. Turn the wrist counterclockwise, pulling the end of the sword back and up.Then with the sword pointing down and left, thread the point in the path of a snake creeping down. Traditional name is Snake Creeps Down to Pierce. The left hand circles up, just as it does for the Yang Snake Creeps Down, then presses down over the right hand.
Pu bu chuan jian
14. Deng Jiao Qian Ci: Qian means forward. Kicking Up and Thrusting Sword. Come up from snake on the left foot, opening arms to ward off. Scoop up the sword handle in both hands and lift the right knee. Thrust level forward (both hands) with the heel kick. When stepping down on the right, lower the end of the sword (point rocks up a bit). Reach to thrust forward with both hands.
This whole movement (and the next) goes toward the back right corner; it travels diagonally.
15. Tiao Bu Ping Ci: Wild Horse Leaping Over Creek (that is the traditional name; the Chinese descriptive name means “jump step level stab”). From the reaching thrust after the kick, hop forward onto the left foot, opening the arms. Hands drop to the sides with the landing. Stab level, left arm high.
Leaping Across the Stream!
16. Zhuan Shen Ping Ci: Turn body level stab. Circle the sword to the left, and turn the wrist counterclockwise to palm down. Do this while shifting left and turning the right toes in. Sword fingers go to the right wrist. Then lead a full turn to the left with the sword fingers, finish in zuo gong bu ping ci (palm up) facing the back. Below:
17. Chuan Jian Xing Bu: Bagua Walking. Block back and up to the right while shifting back. Turn left, pivoting on left heel, and thread the sword across the body to stab to the left. Curl under the right hand to go palm-down on the pull-back; spiral to palm-up on the stab. It’s a little hard to see, below, that his shoulders are facing us but his hips face away. Left arm is behind him (toward the camera).
18. Xing Bu Kou Jian: The right steps across the left and beng jian–flip the wrist to snap the sword up. Here’s where you walk in a big circle and a half. Starting with the left foot, four steps. Then on five, lift the hilt; on six, stab out to the right; on seven open the arms; on eight, bring them together overhead; on nine, circle down and pull the hilt up to the right, pressing down with the left.
Count nine of Bagua Walking
19. Gong Bu Xia Ci: Traditional name is Cat Catches Rat. Head for the back corner. On what would be the tenth step, open out the arms. On eleven, step toward the back corner. On twelve (we’re on the right foot now) stab down with both hands on the sword handle. You gong bu xia ci = right bow stance stab down. Master Tsao notes that with enough space, you can make it fourteen steps, and that’s what he does on the YouTube video — watch :55-1:05 in slow motion.