Zohar 2:3b

Jewish Mysticism
“For the Lord God is sun and shield” (Ps. 84-12), “sun and shield’ refers to the holy covenant- Just as the sun shines and illumines the world, so the holy covenant shines and illumines the body of the person (gufa’ de-var nash), and just as the shield is to protect the person (bar nash), so too the holy covenant is a shield for the person. … He who lies with respect to the holy covenant that is sealed on his flesh is as if he lied with respect to the name of the blessed holy One; the one who lies with respect to the seal of the king lies with respect to the king.

Translated by Elliot Wolfson in “Ontology, Alterity and Ethics in Kabbalistc Anthropology,” Exemplaria (2000)- 129-155.