Charles Ellicott Commentary Exodus 17:7

"And he called the name of the place Massah, and Meribah, because of the striving of the children of Israel, and because they tempted Jehovah, saying, Is Jehovah among us, or not?" — Exodus 17:7 (ASV)

Massah means trial, or temptation, being formed from the root used in Exodus 17:2 (Why do you tempt the Lord?). It is the word translated as “trial” in Job 9:23, and as “ temptation” in Deuteronomy 4:34, Deuteronomy 7:19, Deuteronomy 29:3, and Psalms 95:8.

Meribah means chiding, or quarrel, and is from the root rub, or rib, translated “chide” in Exodus 17:2, and rendered elsewhere generally as “strive,” or “contend.” The name Meribah was also given to the place where water was again produced miraculously by Moses striking the rock (Numbers 20:13). It is this latter “Meribah” to which reference is made in Deuteronomy 33:8 and Psalms 81:7, and which is called by way of distinction in Deuteronomy 32:51, “Meribah-Kadesh.”