|Easton's Bible Dictionary|
Bitterness, a fountain at the sixth station of the Israelites (Exodus 15:23, 24; Numbers 33:8) whose waters were so bitter that they could not drink them. On this account they murmured against Moses, who, under divine direction, cast into the fountain "a certain tree" which took away its bitterness, so that the people drank of it. This was probably the `Ain Hawarah, where there are still several springs of water that are very "bitter," distant some 47 miles from `Ayun Mousa.
Int. Standard Bible Encyclopedia
ma'-ra, mar'-a (marah, "bitter"): The first camp of the Israelites after the passage of the Red Sea (Exodus 15:23 Numbers 33:8 f). The name is derived from the bitterness of the brackish water. Moses cast a tree into the waters which were thus made sweet (Exodus 15:23).
See WANDERINGS OF ISRAEL.
Marah (4 Occurrences)
Exodus 15:23 When they came to Marah, they couldn't drink from the waters of Marah, for they were bitter. Therefore its name was called Marah. (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
Numbers 33:8 They traveled from before Hahiroth, and passed through the midst of the sea into the wilderness: and they went three days' journey in the wilderness of Etham, and encamped in Marah. (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
Numbers 33:9 They traveled from Marah, and came to Elim: and in Elim were twelve springs of water, and seventy palm trees; and they encamped there. (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
Ruth 1:20 And she said unto them, Call me not Naomi, call me Mara; for the Almighty hath dealt very bitterly with me. (See JPS)