“No longer shall your name be called Abram, but your name shall be Abraham; For I have made you the father of a multitude of nations.” Gen. 17:5
“Then God said to Abraham, “As for Sarai your wife, you shall not call her name Sarai, but Sarah shall be her name.”” Gen. 17:15
It is generally thought that the name Abram means “exalted father”, which he becomes, in a sense, through his many descendants. However, a name change in scripture is indicative of a change in fate (Fox, Five Books of Moses) and so the new name Abram receives is more likely to illustrate who he will become, whereas his current name would be descriptive of his life up until that point.
Plaut (The Torah, A Modern Commentary) notes that Abram is likely a contraction of Abi-ram, which means “My father is exalted”. This is a more significant rendering, as it tells us that Abram exalted God. And so the exalting of God was a precursor to the change in destiny he receives with his new name.
Similarly, the general thought is that the name Abraham means “father of a multitude” though it technically does not trace back or translate to that. The Hebrew language uses many puns, most of which we do not pick up on once translated. In this case it is probably what is occurring, as the phrase “father of a multitude” is av-rav-‘am, which is likely where the current understanding of Abraham’s name comes from.
As we see in verse 15, Sarai also receives the new name of Sarah, which denotes royalty and is believed to mean “princess”. This is fitting as we are told in Gen. 17:16 that “kings of peoples will come from her.” Sarah is also the only woman in the bible to receive a new name by God. Sarai and Sarah both mean princess, though the scope of what she is a princess of has expanded.
At first it may not seem noteworthy that both Abraham and Sarah had the letter “H” added to their previous names, however as Plaut notes, the Hebrew “h” with an abbreviation sign stands for “God” in Hebrew writings. So this seemingly mundane change is significant – the addition of the “h” to their names represents the presence of God in their lives from here on.