Pharaoh has a change of heart and pursues his erstwhile slaves. But, The Israelites were marching out "triumphantly" (lit., "beyad rama, with arms held high").
Onkelos renders this expression as (bereish gelei) "with a revealed head," meaning "boldly unafraid," not bothering to shield their heads with helmets or the like.
The Baal Shem Tov's grandson, Rabbi Moshe Chaim Efraim of Sadilkov, pointed out the word for "with a head" (bereish) can be seen as an acronym formed from the first letters of the name Rabbi Shimon bar Yochai, author of the Zohar, the seminal classic of Jewish mysticism. Allegorically, then, this phrase can be understood to mean that "the Israelites will leave [exile] with the revelation of [the teachings of] Rabbi Shimon bar Yochai."
Indeed, in the Zohar itself, the prophet Elijah is quoted as saying those who study the teachings of "this book...the Zohar...will not need to undergo trials [before the final redemption]. Since the Jewish people will, in the future, taste from the Tree of Life, i.e., the Zohar, they will, in this merit, leave exile in mercy, in fulfillment of the verse, 'G-d Himself will lead them, and there will be no alien deity with Him.'"
Rabbi Moshe Chaim Efraim then quotes Rabbi Eliezer Lipa of Chmielnik as saying the bereish can also be seen as an acronym for the Baal Shem Tov's name - Rabbi Yisrael ben Sarah, or Rabbi Yisrael Ba'al Shem.
This accords with the Baal Shem Tov's account of his famous spiritual ascent on Rosh HaShanah of 1746, in which he met the soul of Messiah, who then told him that he would descend to redeem the world "when your teachings will be publicized and revealed throughout the world, and 'your wellsprings spread outward.'"
Remarkably, bereish can also be seen as an acronym for the names of two other sages who played pivotal roles in the dissemination of the teachings of Jewish mysticism: Rabbi Yitzchak ben Shlomo Luria (the Arizal) and the previous Lubavitcher Rebbe - Rabbi Yosef [Yitzchak] ben Shalom Dovber, or Rabbi Yosef [Yitzchak] ben Shterna [Sarah].
The Arizal, in addition to revealing new levels of understanding the teachings of the Zohar, declared that the time had come to promulgate these teachings to the masses rather than restricting their study to the spiritual elite, which had been the practice until his time.
The previous Lubavitcher Rebbe, whose yahrzeit is today, Yud Sevat, initiated the translation of these teachings into modern languages, thereby making them accessible to an even wider public.
Each of these individuals thus revealed the Torah's secrets to a greater extent than had been previously accomplished, and thus brought the Redemption closer.