In Parashat Eikev, Moshe recounts the events following the sin of the golden calf, describing how he broke the stone tablets upon seeing the people worshipping the calf (9:17), and then petitioned God on their behalf, begging Him to forgive them. God accepted Moshe’s prayers, and proceeded to command him, “Go chisel two new stone tablets, like the first ones, and come up the mountain to Me, and make for yourself a wooden ark” (10:1). He then informed Moshe that He would engrave upon the new tablets the same words that He had engraved on the first tablets, and Moshe should then place them in the ark he constructed.
The commentators debate the question of whether this ark is the same ark that was placed inside the Mishkan, as we read in Sefer Shemot (25:25:10-22). Rashi, based on the Midrash (Tanchuma, 10), explains that this was a different ark, which God instructed Moshe to build so he would have where to store the new tablets until the permanent ark would be built. Once the permanent ark was built, the tablets were placed in the new ark. That new ark was permanently kept inside the Mishkan – and, later, inside the Beit Ha-mikdash – whereas the other ark was brought with Benei Yisrael when they went out to battle. Rashi writes that when Benei Yisrael brought the ark with them in their ill-fated war against the Pelishtim, when the ark was captured and the Mishkan in Shilo was destroyed (Shemuel I, chapter 4), this marked an exceptional case when the soldiers brought the ark from the Mishkan to the battlefield – for which they were gravely punished. Another exception is noted by Tosafot (Eiruvin 63b), who make reference to Benei Yisrael’s war against Amon, during which King David committed the sin with Batsheva. Uriya, Batsheva’s husband, refused to go home during the war despite being granted special permission by the king, explaining that it would be inappropriate to spend the night with his wife while the ark was in the battlefield (Shemuel II 11:11). Tosafot explain that this was an exceptional instance when the ark from the Mishkan was brought with the troops to battle. In any event, according to Rashi, there were two arks – one which generally remained inside the Mishkan, and another which was taken out to battle.
The Ramban, however, notes that this represents the minority opinion of Reish Lakish, cited by the Yerushalmi (Shekalim 6:1), whereas according to the majority opinion, there was only a single ark. After all, the Ramban asks, if there were two separate arks, then what was the first used for after the second ark was built and the tablets were placed in it? As the Ramban himself acknowledges, the answer is given by Reish Lakish in the Yerushalmi – that the first ark was used to house the shivrei luchot – the broken pieces of the first tablets which Moshe brought from Mount Sinai and shattered upon seeing the worship of the golden calf. However, the Ramban notes that the Gemara, in several contexts (Bava Batra 14b, Menachot 99a), speak of the shivrei luchot being stored together with the second set of luchot in the ark which was in the Temple. The shivrei luchot seem to have been stored in the same ark as the second tablets, not in a separate ark, calling into question Reish Lakish’s opinion.
The simplest answer, seemingly, is that the passages in the Gemara that describe the shivrei luchot being stored together with the second tablets reflect the majority view in the Yerushalmi, which does not accept Reish Lakish’s opinion, that there were two arks. However, Tosafot, both in Masekhet Eiruvin (63b) and in the Da’at Zekeinim commentary here in Parashat Eikev, suggest reconciling Reish Lakish’s view with the Gemara’s statement that the shivrei luchot were stored in the Temple together with the second tablets. They explain that once the permanent Temple was built in Jerusalem, the shivrei luchot were moved from the ark in which they had been stored into the ark in the Mikdash, where they permanently remained. The two-ark system was in place only until the building of the Beit Ha-mikdash, at which point the shivrei luchot and second tablets were stored together, for all time.
Regardless, the Ramban interprets this verse here in Parashat Eikev differently. In his view, when Moshe recalls God instructing him, “and you shall make a wooden ark,” this refers to the command to construct the Mishkan. Upon announcing His forgiveness for the sin of the golden calf, God informed Moshe that His earlier command to construct a Mishkan was once again relevant, now that the people were forgiven for their sin. Moshe mentioned this in brief by recalling the command to build an aron, since the aron was, in the Ramban’s words, “the primary objective of the entire Mishkan.” According to the Ramban, then, Moshe speaks here of the lone ark which was kept in the Mishkan, and his point is that in response to his pleas, God informed him that Benei Yisrael should now proceed with the project to construct a site where He would dwell among them.