Quoting Commentary for I Samuel 4:8

ועשית לך ארון עץ, “and make a wooden ark for yourself!”. Moses reports that he first made the ark (compare verse 3) and only after that did he carve out the Tablets. He followed this sequence in order to have a “home” ready for the Tablets when he would return with them from the mountain. If he had not first made the ark where would he put the Tablets when he arrived among the people with them? Our sages have a tradition that the “ark” mentioned by Moses in verse 5 was the one that he had made immediately after receiving the instructions to carve out the second set of Tablets. In other words, this was not the same Ark which Betzalel was instructed to make for the Tabernacle in Exodus 25,10 (based on Tanchuma Eikev 10).
The ark which Moses made was strictly temporary in order to have a place for the Tablets to be put pending the instructions to build the Tabernacle and to make a permanent home for the Tablets. The wooden ark made by Moses was the ones the people would take with them when they went to war. The Ark made by Betzalel was removed from the Tabernacle (except during the journeys when the Tabernacle itself was dismantled) only at the express command of G’d when the people marched around Jericho with the priests carrying the Holy Ark in front of them (Joshua 6,12). When, several hundreds of years later, the sons of the High Priest Eli took it upon themselves to take the Holy Ark to war with them against the Philistines, the Ark was captured and the sons of Eli died as a punishment for their high handed action. (Samuel I 4,8 describes that although, initially the Philistines were frightened of the Ark, they fought the Israelites and were victorious, capturing the Ark).
The ark (box) made by Moses contained (initially) both the Tablets and the broken pieces of the original Tablets which Moses had smashed. After Betzalel made the Holy Ark for the Tabernacle the contents of Moses’ ark were transferred to it. This is the meaning of Exodus 25,16: “you will place inside the Ark the testimony which I shall give you.” Even though the Talmud in Baba Batra 14 states: “there was nothing inside the Holy Ark except the two Tablets,” this is not to exclude the broken pieces of the first Tablets, as whenever two restrictive clauses are employed consecutively, the meaning is that something additional is meant, in this case the remnants of the first Tablets. This was after the Temple of Solomon had been built. As long as the Tabernacle of Betzalel functioned as the Temple, the Holy Ark contained the second set of Tablets whereas Moses’ ark contained the broken pieces of the first set of Tablets. (Compare Tosafot Eyruvin 63. Tosafot base themselves on the verse quoted by the Talmud in Baba Batra which appears in Kings I 8,9.)

But the ten miracles that were performed for our ancestors in Egypt are their salvation from the ten plagues and that each of the ten plagues were specifically on the Egyptians and not on Israel. And these are miracles without a doubt. And the language of the Torah in each and every plague is that the Holy One, blessed be He, brought it [only] on the Egyptians. Except for the plague of lice - as [there] it did not make this clear, but it is known that He did not punish Israel. Rather [the lice] were found with [the Israelites as well], but they did not distress them. And so did the sages elucidate. But with the other plagues, the matter was clarified [in the text]. It stated about the blood (Exodus 7:21), "and the Egyptians could not drink water from the river" - a proof that that the damage reached them alone. And it stated with the frogs (Exodus 7:28), "and they will come into your house and into your bedrooms, etc." And it stated with the mixture of animals (Exodus 8:18), "And I will distinguish on that day the Land of Goshen, etc." And it stated about the pestilence (Exodus 9:6), "but of the livestock of the Israelites not one died." And it sated about the boils (Exodus 9:11), "as the boils were upon the magicians and and upon all of Egypt." And it stated with the hail (Exodus 9:26), "Only in the Land of Goshen, where the Israelites were, there was no hail." And it stated with the locusts (Exodus 10:14), "And locusts went up upon all the Land of Egypt." And it stated with darkness (Exodus 10:23), "and for all the children of Israel, there was light in their dwellings." But the ten miracles that were at the Sea is a received tradition. The first is the splitting of the water like the simple understanding of the verse, "and the water split" (Exodus 14:21). The second is that after the sea split, it became like a tent until it turned into a type of roof - and not of beams and not slanted - and the path was as if there was a hole in the water and the water was on the right and on the left and on top. It is [like] the statement of Habakuk 3:14, "You have pierced with his rods, the head of his rulers." The third is that its ground became hard and solid, as it states (Exodus 14:29), "walked on dry land" - and there did not remain any clay and mud like in other rivers. The fourth is that the paths of the Egyptians were in quicksand, and that is its stating (Habakuk 3:14), "the clay of great waters." The fifth is that it split into twelve paths like the number of tribes like a curved bow, as per this drawing. And that is its stating (Psalms 136:13), "To tear the Reed Sea into pieces." The sixth is that the water congealed and became as hard as boulders. And about this, it stated (Psalms 74:13), "you broke the head of the 'sea monsters' upon the waters" - meaning to say that the waters hardened to the point that they went back in such a way that heads would break on them. And the seventh is that it did not congeal like the solidifying of other waters that congeal - meaning to say [into] one piece, but rather [into] many pieces, as if they were [building] stones and they were arranged some on top of others. And that is its stating (Psalms 74:13), "You crumbled the sea with Your power." The eighth is that it congealed like glass or onyx - meaning to say, it was clear to the point that some of [the tribes] would see each other in their crossing it. And this is its stating (Psalms 18:12), "the darkness of the waters, the clouds of the sky," which is to say that the gathering of waters was 'like the essence of the sky in purity' - which is clear. The ninth - that sweet water would flow from it and they would drink it. The tenth is that it would congeal at the time that it flowed, after they took what they drank from it - to the point that it would not fall to the ground. And that is its stating (Exodus 15:8), "they stood up like a flowing stack" - meaning to say the thing that was flowing congealed in the heart of the sea. And in the tradition we found that more plagues came upon the Egyptians at the Sea than the plagues that came upon them in Egypt. And the hint to this is in its stating (I Samuel 4:8), "He is the same God who struck the Egyptians with every plague in the wilderness" - meaning to say in the Wilderness of the Reed Sea. But the ten trials that our ancestors tested the Omnipresent are all words of Scripture. The first is at the Sea in their saying "Are there no graves in Egypt" (Exodus 14:11). And the second is at Marah - that is its stating (Exodus 15:24), "And they complained about Moshe, saying, 'What will we drink?'" And the third is in the Wilderness of Sin when they asked for the manna. And that is its stating (Exodus 16:3), "And who will give that our death be at the hand of God, etc." And the fourth is their leaving manna over until the morning. And that is its stating (Exodus 16:20), "and men left over from it until the morning." And the fifth is their rebellion in seeking manna on the Shabbat day, as it is stated (Exodus 16:27), "And it was on the seventh day some of the people went out to gather." And the sixth is their rebellion at Refidim, also over water. And the seventh is at Chorev with the story of the [golden] calf. And the eighth is at Taverah when they become doubtful at that place with the speaking of the grumblers. And that is its saying (Numbers 11:1), "And the people were like grumblers." And the ninth is at Kivrot HaTaavah (the graves of desire), when they asked for meat - its saying (Numbers 11:4), "And the mixed multitude that was within them desired a desire." And the tenth is in the Wilderness of Paran with the matter of the spies. And there it stated (Numbers 14:22), "and they have tried Me these ten times and they did not listen to My voice."

V. 6. נאדרי. Erwägen wir die Bedeutung אדר als Mantel, ferner Stellen wie נאור אתה ,אדיר Ps, 76. 5, אדירים משברי ים (daselbst 93, 4), מלכים אדירים (daselbst 136, 18) אוי לני מי יצילנו מיד האלקי׳ האדירים האלה (Sam. I. 4, 8) und andere Stellen mehr, in welchen überwiegend nicht der Charakter der Anmut, der Schönheit, der Pracht, sondern der einer außerordentlichen Macht durch אדיר seinen Ausdruck findet, erwägen wir ferner die Verwandtschaft mit עדר und חדר, die ein abschließendes Sammeln zu einem Haufen oder in eine Umgrenzung bedeuten: so bezeichnet אַדִיר einen durch weiteres Machtgebiet über alle andere hervorragenden, von allen andern gesonderten und ausgezeichneten Mächtigen. Es ist der Mächtige ohnegleichen, und הֵאָדֵר: als sondergleichen mächtig, in einer Machtfülle sondergleichen offenbar werden. — Es heißt nicht בְכֹח sondernבָכּחַ , heißt auch nicht הָאוֹיֵב, sondern ,אוֹיֵב daher: deine durch diese hier geübte Kraft in einer Machtgröße sondergleichen offenbar gewordene Rechte wird fortan jeden Feind schrecken. כח ist das Vermögen, etwas zu tun. Du hast hier gezeigt, was du vermagst, gezeigt, daß in dir eine Macht vorhanden ist, die selbst die riesigste soziale Gewalt zu fürchten hat, sobald sie dem von dir gewollten Menschenheile feindlich ist. Daher auch ימין die dem Bedrohten helfende Rechte. Die Anschauung, die in ימין in der Rechten Gottes, die helfende, Heil spendende Gottesmacht und in יד, der Linken, die strafende, vernichtende erblickt, quillt tief aus dem jüdischen Gottbewusstsein. Gott zeigt seine eigentliche Macht und Größe schaffend und helfend, Leben und Segen gebend, nicht strafend und vernichtend. Von ihm ausgehende Strafe und Vernichtung ist selbst nur ein Weg zum Heile und zum Segen. Seine Linke steht im Dienste seiner Rechten.