In Marah they receive certain mitzvot . The people complain that they ate better food in Egypt. Hashem sends quail for meat and provides manna, a miraculous bread that falls from the sky every day except Shabbat. On Friday a double portion descends to supply the Shabbat needs. No one is able to obtain more than his daily portion, but manna collected on Friday suffices for two days so the Jews can rest on Shabbat.
Some manna is set aside as a memorial for future generations.
When the Jews again complain about a lack of water, Moshe miraculously produces water from a rock. Then Amalek attacks. Joshua leads the Jews in battle while Moshe prays for their welfare. The night was wet. The road was like an ice rink.