Origen, on Num 33:8

“And departing from Phihahiroth, they passed through the midst of the sea into the wilderness: and having marched three days through the desert of Etham, they camped in Mara.”

“And so they camped at the Bitter Waters [Marah]. Do not be terrified or afraid when you hear of Bitter Waters. "For the moment all discipline seems bitter rather than pleasant; later it yields the sweetest and most peaceful fruit of righteousness to those who have been trained by it," as the apostle teaches. Then too, the unleavened bread is commanded to be eaten with bitter herbs; nor is it possible to attain the Promised Land unless we pass through bitterness.”

Imported from an open dataset — not yet checked against the printed edition.