Exodus 15:23

When they came to Marah, they could not drink the waters of Marah, for they were bitter; therefore it was named Marah.

Numbers 33:8

They journeyed 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 camped at Marah.

Ruth 1:20

She said to them, “Do not call me Naomi; call me Mara, for the Almighty has dealt very bitterly with me.

Treasury of Scripture Knowledge

Summary

And when they came to Marah, they could not drink of the waters of Marah, for they were bitter: therefore the name of it was called Marah.

Bible References

Marah

Numbers 33:8
They journeyed 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 camped at Marah.
Ruth 1:20
She said to them, “Do not call me Naomi; call me Mara, for the Almighty has dealt very bitterly with me.