Or HaChaim on Deuteronomy 10:5/אור החיים על דברים י׳:ה׳

1 כאשר צוני השם, "as G'd commanded me." Moses meant that all the time it took for him to bring the Tablets to the people and to place them in the ark constructed by Bezalel, the Tablets remained in the ark which he had constructed and taken up to Mount Sinai with him.