What do Yahweh and Jehovah mean?

1 According to Morrish's New and Concise Bible Dictionary, this Name is derived from havah, 'to exist,' and may be expanded into 'Who is, Who was, and is to come.' God thus reveals Himself in time as the ever-existing One: that is, in Himself eternally, He is always the same. This is also emphasised in the Name 'the Same.'

JEHOVAH

This is the second name of God found in the Old Testament. Its first occurrence is found in Genesis 2:4. It is translated GOD some 300 times, and LORD about 6,000 times. Its meaning is, He, that always was, that always is, that always will be, the Eternal. It is far more numerously mentioned in Scripture than any other name of God. Wherever the reader finds the name of GOD printed in capital letters, or the name LORD printed likewise in capital letters in his Bible, he may in both cases know that it refers to Jehovah.

"Jehovah" is full of the deepest and tenderest suggestions. Etymologically, it means "The One who Exists," perhaps in the simplest way in which it could be expressed, declaring the eternity of God, in contrast with His entire creation, sentient and inanimate, which is finite. It is the self-existent One, the Absolute, who Himself is the Cause, Author and End of all things; the "Alpha and Omega," "the First and the Last," by whom and for whom are all things — the One who "is, and was, and is to come;" the One of whom the Psalmist says, "From everlasting to everlasting, Thou art God." There is, however, in this name "Jehovah" an etymological suggestion of futurity hinted at by the presence of the first letter Yodh, the New Testament "jot" of Matthew 5. It might be rendered "The One who will be," as though suggesting a revelation of Himself in far fuller measure than was enjoyed when first His name was declared. Indeed, God reminded Moses that the revelation of Himself as "Jehovah," in the significance of this name, was something new.

— The dread and sacred Name Jehovah signifies underived existence, the Self-Existing One. To Israel the Name was explained as “I AM THAT I AM” (Ex. 3:14); to Gentiles as “Him which is, and which was, and which is to come” (Rev. 1:4; 4:8). It is a Name of ineffable grandeur, and one which Israel was made fully acquainted with from the commencement of her history (Ex. 6:3). It is God’s memorial Name, even to generations yet unborn. “Which is” implies independent, unchangeable existence. “Which was” intimates Jehovah’s relation to the past. “Which is to come” shows His connection with the future. God’s relation to the universe in its vastness and greatness, as also in its minuteness, is a grand and invigorating truth.

Jehovah. This is a name of relationship with men, especially with Israel, taken by God in time. It is derived from havah, 'to exist,' and may be expanded into 'who is, who was, and is to come.' God thus reveals Himself in time as the ever-existing One: that is, in Himself eternally, He is always the same: cf. Heb. 1:12. The above 'relationship' may be seen in the change from Elohim, the Creator, in Gen. 1, to Jehovah Elohim in Gen. 2, when man was brought into relationship with God. Again in Gen. 7:16 Elohim ordered Noah to make the ark but Jehovah shut him in. Unfortunately the name Jehovah is seldom employed in the A.V. It is generally represented by LORD (sometimes GOD) printed in small capitals.* There is a contraction of Jehovah into Jah, also translated in the A.V. by LORD, except in Ps. 68:4, where Israel is exhorted to sing unto God, and "extol him by his name JAH." Jah signifies the absolute supremacy of the self-existing One; whereas Jehovah was the name made known to Israel, and on which they could count. "God said unto Moses, I AM THAT I AM," Ex. 3:14, where the word is Ehyeh, which is from the same root as Jehovah, the Eternal existing One; He that was, and is, and the coming One.

Jehovah is the name He takes with Israel, but this is the application of eh'yeh to continuance - existence relative to those in time.

As to the names of God, we find Jah, Jehovah, Eh'yeh. I do not know how far I am justified as to the difference, for they are from the same root. In Jah we have the name in itself - simply, "He who exists." Eh'yeh is the expression of it by Himself. So "I" comes in - there is the conscious will of existence, which, in a divine Being, goes with the existence in itself. In Jehovah, Jah is developed into "Is, was, and is to come" - the Securer of promise, in which we have continued existence, time coming into account - continuity present, past and future.

Jehovah is the name of which the inspired translation is given in the third of Exodus — "I am:" expanded to its full significance in the book of Revelation as, "He which is, and which was, and which is to come." Thus in immutable existence He follows out the changes of created being, propping up creaturehood with the strength of eternity. "By Him all things consist." As in relation with a redeemed people — Israel — how blessed and re-assuring this His covenant-name!

The term Jehovah is never applied to any other than the Most High; it may be derived so as to imply essential existence — the existing one.

Jehovah (2), a name for relationship in blessing between the self-existent I AM and Israel.