Charles Ellicott Commentary Isaiah 63:11

"Then he remembered the days of old, Moses [and] his people, [saying], Where is he that brought them up out of the sea with the shepherds of his flock? where is he that put his holy Spirit in the midst of them?" — Isaiah 63:11 (ASV)

Then he remembered ... —The readings vary, and the construction is difficult. Probably, the best rendering is, His people remembered the ancient days of Moses. In any case, it is Israel that remembers, and by that act repents. (Compare to the tone and thoughts of Psalms 77, Psalms 78, Psalms 105, and Psalms 106)

With the shepherd ... —Many manuscripts, as noted in the margin, give the plural, “shepherds,” probably as including Aaron and Miriam as among the leaders and deliverers of the people. (Micah 6:4.)

Within him. —Not Moses only, but Israel collectively. Note the many instances of the gift of the Spirit, to Bezaleel (Exodus 35:31), to the Seventy Elders (Numbers 11:25), to Joshua (Deuteronomy 34:9). (Compare to Nehemiah 9:20.)