Exodus 15:23 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.
Numbers 33:8 And they departed from before Pi-hahiroth, and passed through the midst of the sea into the wilderness, and went three days' journey in the wilderness of Etham, and pitched in
Marah.