John Wesley on Exodus 6:2

l am Jehovah - The same with I am that I am, the fountain of being and blessedness, and infinite perfection. The patriarchs knew this name, but they did not know him in this matter by that which this name signifies. God would now be known by his name Jehovah, that is, A God performing what he had promised, and so giving being to his promises. A God perfecting what he had begun, and finishing his own work. In the history of the creation God is never called Jehovah, till the heavens and the earth were finished, Gen 2:4. When the salvation of the saints is compleated in eternal life, then he will be known by his name Jehovah, Rev 22:13, in the mean time they shall find him for their strength and support, El - shaddai, a God All - sufficient, a God that is enough.