For God is After an Hand’: Piers Plowman B. 17.138-205.
The extended metaphor of the Trinity as a hand is unusual in identifying the Son, rather than the Holy Spirit, as the finger. WL’s identification of the palm with the Holy Spirit, while apparently without explicit source, seems consonant with the doctrine of filioque, the procession of the Spirit from the Father and the Son, but the Samaritan’s image, in emphasizing the Holy Spirit’s importance, comes close to implying that procession derives from the Holy Spirit. The metaphor is intended to show Will that love is as essential to the working of the Trinity as it is in human affairs, and that the Holy Spirit embodies this love, i.e., that which exists between the Father and the Son as well as in caritas among mankind.