Touch always belongs to the wind (as its quality). That is perceived by the skin. The wind that always lives in the skin has been appointed in apprehending touch.
वायव्यस्तु सदा स्पर्शस्त्वचा प्रज्ञायते च सः। त्वक्स्थश्चैव सदा वायुः स्पर्शने स विधीयते॥