Because he hath set his love upon me (see Deuteronomy 7:7; Deuteronomy 10:15). "By a sudden and effective transition," as Professor Cheyne remarks, "Jehovah becomes the speaker" of the concluding strophe.
It is not enough that the faithful should encourage each other by their anticipations of God's coming mercies, God himself now speaks by the mouth of his prophet, and makes promises in his own Person.
I will deliver him. A ratification of Psalms 91:3, Psalms 91:7, Psalms 91:10-15. I will set him on high; i.e. "exalt him above his fellows"—"bring him to honour." Because he hath known my Name. "Knowing God's Name" is nearly equivalent to knowing him.
It implies, besides knowledge, faith and trust in the Almighty.