Charles Ellicott Commentary Isaiah 63:10

"But they rebelled, and grieved his holy Spirit: therefore he was turned to be their enemy, [and] himself fought against them." — Isaiah 63:10 (ASV)

Vexed his holy Spirit ... —Literally, his Spirit of holiness. So St. Paul speaks of Christians as “grieving the Holy Spirit.” Here, and in Psalm 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, by its very nature, 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.