Isaiah 63:10

Vexed his holy Spirit... — Literally, his Spirit of holiness. So St. Paul speaks of Christians as “grieving the Holy Spirit.” Here, and in Psalms 51:11, as in the “Angel of the Presence,” we may note a foreshadowing of the truth of the trinal personality of the unity of the Godhead, which was afterwards to be revealed. That which “vexed” the Holy Spirit was, in the nature of the case, the unholiness of the people, and this involved a change in the manifestation of the Divine Love, which was now compelled to show itself as wrath.