There are 2 critical nights in the Exodus story. The first in Egypt - when the Israelites slaughtered and ate the Paschal lamb and the 10th plague was carried out against the Egyptian first-born. The second - shortly after the journey of the Israelites began - when they reach the Sea.
(כב) וּלְקַחְתֶּ֞ם אֲגֻדַּ֣ת אֵז֗וֹב וּטְבַלְתֶּם֮ בַּדָּ֣ם אֲשֶׁר־בַּסַּף֒ וְהִגַּעְתֶּ֤ם אֶל־הַמַּשְׁקוֹף֙ וְאֶל־שְׁתֵּ֣י הַמְּזוּזֹ֔ת מִן־הַדָּ֖ם אֲשֶׁ֣ר בַּסָּ֑ף וְאַתֶּ֗ם לֹ֥א תֵצְא֛וּ אִ֥ישׁ מִפֶּֽתַח־בֵּית֖וֹ עַד־בֹּֽקֶר׃
(ל) וַיָּ֨קָם פַּרְעֹ֜ה לַ֗יְלָה ה֤וּא וְכָל־עֲבָדָיו֙ וְכָל־מִצְרַ֔יִם וַתְּהִ֛י צְעָקָ֥ה גְדֹלָ֖ה בְּמִצְרָ֑יִם כִּֽי־אֵ֣ין בַּ֔יִת אֲשֶׁ֥ר אֵֽין־שָׁ֖ם מֵֽת׃
(מב) לֵ֣יל שִׁמֻּרִ֥ים הוּא֙ לַֽיהוָ֔ה לְהוֹצִיאָ֖ם מֵאֶ֣רֶץ מִצְרָ֑יִם הֽוּא־הַלַּ֤יְלָה הַזֶּה֙ לַֽיהוָ֔ה שִׁמֻּרִ֛ים לְכָל־בְּנֵ֥י יִשְׂרָאֵ֖ל לְדֹרֹתָֽם׃
(22) Take a bunch of hyssop, dip it in the blood that is in the basin, and apply some of the blood that is in the basin to the lintel and to the two doorposts. None of you shall go outside the door of his house until morning.
(30) And Pharaoh arose in the night, with all his courtiers and all the Egyptians—because there was a loud cry in Egypt; for there was no house where there was not someone dead.
(42) That was for יהוה a night of vigil to bring them out of the land of Egypt; that same night is יהוה’s, one of vigil for all the children of Israel throughout the ages.
This was a night of שִׁמֻּרִים - a night of vigil, guarding, keep watch, paying attention - for both the Israelites and God. The Israelites spent these dark night hours in their homes -- sheltering-in-place, needing to believe that doing so would keep them safe. And all around them - every Egyptian household cried out because someone had died.
(כא) וַֽיהוָ֡ה הֹלֵךְ֩ לִפְנֵיהֶ֨ם יוֹמָ֜ם בְּעַמּ֤וּד עָנָן֙ לַנְחֹתָ֣ם הַדֶּ֔רֶךְ וְלַ֛יְלָה בְּעַמּ֥וּד אֵ֖שׁ לְהָאִ֣יר לָהֶ֑ם לָלֶ֖כֶת יוֹמָ֥ם וָלָֽיְלָה׃ (כב) לֹֽא־יָמִ֞ישׁ עַמּ֤וּד הֶֽעָנָן֙ יוֹמָ֔ם וְעַמּ֥וּד הָאֵ֖שׁ לָ֑יְלָה לִפְנֵ֖י הָעָֽם׃ (פ)
(21) יהוה went before them in a pillar of cloud by day, to guide them along the way, and in a pillar of fire by night, to give them light, that they might travel day and night. (22) The pillar of cloud by day and the pillar of fire by night did not depart from before the people.
In the very first stages of the Israelites' journey out of Egypt, we learn about the physical presence of God which leads them on their way. A pillar of cloud by day; a pillar of fire by night. As they approach the sea, this beacon changes and shifts.
(יט) וַיִּסַּ֞ע מַלְאַ֣ךְ הָאֱלֹהִ֗ים הַהֹלֵךְ֙ לִפְנֵי֙ מַחֲנֵ֣ה יִשְׂרָאֵ֔ל וַיֵּ֖לֶךְ מֵאַחֲרֵיהֶ֑ם וַיִּסַּ֞ע עַמּ֤וּד הֶֽעָנָן֙ מִפְּנֵיהֶ֔ם וַיַּֽעֲמֹ֖ד מֵאַחֲרֵיהֶֽם׃ (כ) וַיָּבֹ֞א בֵּ֣ין ׀ מַחֲנֵ֣ה מִצְרַ֗יִם וּבֵין֙ מַחֲנֵ֣ה יִשְׂרָאֵ֔ל וַיְהִ֤י הֶֽעָנָן֙ וְהַחֹ֔שֶׁךְ וַיָּ֖אֶר אֶת־הַלָּ֑יְלָה וְלֹא־קָרַ֥ב זֶ֛ה אֶל־זֶ֖ה כָּל־הַלָּֽיְלָה׃ (כא) וַיֵּ֨ט מֹשֶׁ֣ה אֶת־יָדוֹ֮ עַל־הַיָּם֒ וַיּ֣וֹלֶךְ יְהוָ֣ה ׀ אֶת־הַ֠יָּם בְּר֨וּחַ קָדִ֤ים עַזָּה֙ כָּל־הַלַּ֔יְלָה וַיָּ֥שֶׂם אֶת־הַיָּ֖ם לֶחָרָבָ֑ה וַיִּבָּקְע֖וּ הַמָּֽיִם׃ (כב) וַיָּבֹ֧אוּ בְנֵֽי־יִשְׂרָאֵ֛ל בְּת֥וֹךְ הַיָּ֖ם בַּיַּבָּשָׁ֑ה וְהַמַּ֤יִם לָהֶם֙ חֹמָ֔ה מִֽימִינָ֖ם וּמִשְּׂמֹאלָֽם׃
(19) The angel of God, who had been going ahead of the Israelite army, now moved and followed behind them; and the pillar of cloud shifted from in front of them and took up a place behind them, (20) and it came between the camp of the Egyptians and the camp of Israel. Thus there was the cloud, and the darkness, and it lit up the night, and the one could not come near the other all through the night. (21) Then Moses held out his arm over the sea and יהוה drove back the sea with a strong east wind all that night, and turned the sea into dry ground. The waters were split, (22) and the Israelites went into the sea on dry ground, the waters forming a wall for them on their right and on their left.
The second critical night is this moment -- when the Israelites are fleeing, the Egyptians bearing down behind them as they arrive at the sea. This passage starts with a very confusing image -- the pillar which is a messenger of God shifts position and moves between the Egyptians and the Israelites and it seems to cast both darkness and light, to be both cloud and fire. One commentary explains that the pillar was fire on the side of the Israelites casting light ahead through the darkness so they could see their way and the pillar was a cloud of darkness on the side facing the Egyptians making it impossible for them to see.
Even with light coming from behind them, the Israelites had to move forward into the darkness, needing to believe that doing so would keep them safe. Whether the sea parted with Moshe's raised arm or (as the Midrash would have it) with Nachshon walking into the water, they were moving into danger between two walls of water which could come crashing down.
This year, in the midst of the COVID pandemic, we are living in a deep darkness, an intense night of danger and uncertainty. Most of us must choose the courage the Israelites showed on that fateful night in Egypt -- to stay in our homes, to shelter-in-place, to seek safety within our four walls. By doing so, we strive to protect ourselves and our loved ones from death and grief. Some of us must choose the courage the Israelites showed on that night at the edge of the sea -- to take steps out into the darkness, to pray that the seabed is firm and even, and that the walls of water will hold steady when we walk beneath them. For the healthcare workers, the grocery and restaurant employees and civil servants, the first responders, the hospital employees (from janitors to transporters) -- for all of us who must have the courage to walk into the darkness, we rely on all of you who must have the courage to stay at home.
In this moment, let us have compassion for each household which is crying out in grief as we are likely to be among them soon enough. And let us pray that the courage we show - by staying in or going out - continues to save lives.