This is a superscription that tells about the psalm. Some scholars say that this is part of the scripture and some say that it is not. (See "What are Superscriptions in Psalms" in [Introduction to Psalms](../front/intro.md).)
These two phrases mean basically the same thing and emphasize how much he will praise Yahweh. Alternate translation: "I will praise Yahweh with all that I am" (See: [[rc://en/ta/man/jit/figs-parallelism]])
"all of me" or "all that I am." David uses this phrase to refer to himself and to emphasize his devotion to Yahweh. (See: [[rc://en/ta/man/jit/figs-synecdoche]])