Why do some translations of Qur'an 79:30 talk about the Earth being egg-shaped?

Question

A few translations of Qur'an 79:30 say that the Earth is egg-shaped. For example:

And after that He has spread out the earth in the egg-shape (for habitability). -- translation by Ali Ünal

And more, He has extended the earth (far and wide also in the shape of an egg): -- translation by Syed Vickar Ahamed

First, the Earth is not egg-shaped (it's very close to a sphere; an oblate spheroid with a small eccentricity), which is apparent from photographs, e.g.:

But I'm more interested in if the Arabic in Qur'an 79:30 implies "egg-shaped", like the translations above state.

وَالْأَرْضَ بَعْدَ ذَٰلِكَ دَحَاهَا

It doesn't look like it; the "literal" translation is listed as:

And the earth after that He spread it.

which doesn't say anything about egg-shaped. It therefore seems to be an unexpected translation, so I'm puzzled as to how this came about. There's more than one translation that says this, so there may be something I'm unaware of here.

Question: Why do some translations of Qur'an 79:30 talk about the Earth being egg-shaped?

Answer 1

I believe this is a metaphorical use of the word.

• دَحَا shares root (i.e. دحو) with الأدحيّ which is used for the place in sand where female ostrich lays eggs. It is named so because it spreads/levels the place with its feet before laying egg. Therefore, original meaning of the root (to spread, to level) is present in الأدحيّ.
• It is common in the literature to use the word for the container to mean the contained e.g. إذا شربت أربعة أكؤس جررت مئزري i.e. when I had drunk four cups I drag my loincloth (on the ground). In this example, cup means wine or something like that.

I believe the translators who have translated دَحَا as egg-shaped have made use of the above two points.