At that time, God said to me, 'Carve out two stone tablets like
the first ones, and come up to Me on the mountain. Make yourself
a wooden ark. Ba'et hahi amar Adonay elay psol-lecha shney-
luchot avanim karishonim va'aleh elay haharah ve'asita lecha
aron ets. Exodus 34:1. This was on 1 Elul, after Moses had
prayed for the people forty days (Rashi). Some say that this was
a temporary ark, that was used until the golden ark mentioned in
Exodus 25:10 was made (Ramban; Bachya). According to others,
this ark was used for the broken tablets, and it was taken out
in war (Rashi; see Numbers 10:33). Some say that Moses made the
basic ark out of acacia wood, and then Betzalel covered it with
gold (Malbim; cf. Ibn Ezra; Yoma 3b, 72b).