Abarbanel, Exodus 17:0, Commentary on the Torah (Italy, between 1492–1509); quoted in Nehama Leibowitz, New Studies in Shemot (Exodus) (Jerusalem: Haomanim Press, 1993), volume 1, page 285; reprinted as New Studies in the Weekly Parasha (Lambda Publishers, 2010).
Fred Reiss, The Standard Guide to the Jewish and Civil Calendars: A Parallel Jewish and Civil Calendar from 1899 to 2050 with Parashiyyot and Haftarot and Candle-Lighting Times for Selected Cities (West Orange, New Jersey: Behrman House, 1986); “Parashat Beshalach,” Hebcal.
Maimonides, Mishneh Torah, Negative Commandment 321 (Cairo, Egypt, 1170–1180), in Maimonides, The Commandments: Sefer Ha-Mitzvoth of Maimonides, translated by Charles B. Chavel (London: Soncino Press, 1967), volume 2, page 296; Charles Wengrov, translator, Sefer HaHinnuch: The Book of [Mitzvah] Education (Jerusalem: Feldheim Publishers, 1991), volume 1, pages 137–41.