While Aaron undoubtedly gathered manna into a jar at that time, the depositing of it before the Testimony had to wait until Moses made the Ark and placed the tablets in it.
Meskipun Harun pada waktu itu pasti menyimpan manna dalam sebuah tempayan, ia baru bisa menaruhnya di sana setelah Musa membuat Tabut dan menyimpan lempeng - lempeng di dalamnya.