Charles Ellicott Commentary Isaiah 63:7

"I will make mention of the lovingkindnesses of Jehovah, [and] the praises of Jehovah, according to all that Jehovah hath bestowed on us, and the great goodness toward the house of Israel, which he hath bestowed on them according to his mercies, and according to the multitude of his lovingkindnesses." — Isaiah 63:7 (ASV)

I will mention ... —The words begin an entirely new section, of the nature of a psalm of thanksgiving for redemption (Isaiah 63:16). Possibly, in the arrangement of the book it was thought that such a psalm followed rightly on the great dramatic dialogue which represented the victory of the Redeemer. The psalm begins, according to the implied rule of Psalms 50:23, with praise, and passes afterward to narrative and supplication.