Tafseer of the verse “Then He Istawa (rose over) towards the heaven when it was smoke, and said to it and to the earth: ‘Come both of you willingly or unwillingly.’ They both said: ‘We come, willingly.’”

Allah, may He be glorified and exalted, says (interpretation
of the meaning): 

“Say (O
Muhammad (blessings and peace of Allah be upon him)): Do you verily
disbelieve in Him Who created the earth in two Days and you set up rivals
(in worship) with Him? That is the Lord of the Alameen (mankind, jinns and
all that exists).

He placed therein (i.e. the earth) firm mountains from above
it, and He blessed it, and measured therein its sustenance (for its
dwellers) in four Days equal (i.e. all these four days were equal in the
length of time), for all those who ask (about its creation).

Then He Istawa (rose over) towards the heaven when it was
smoke, and said to it and to the earth: ‘Come both of you willingly or
unwillingly.’ They both said: ‘We come, willingly.’

Then He completed and finished from their creation (as) seven
heavens in two Days and He made in each heaven its affair. And We adorned
the nearest (lowest) heaven with lamps (stars) to be an adornment as well as
to guard (from the devils by using them as missiles against the devils).
Such is the Decree of Him the All-Mighty, the All-Knower”

[Fussilat 41:9-12]. 

Here Allah, may He be exalted, tells us that He created the
earth in two days, then “He
placed therein (i.e. the earth) firm mountains from above it, and He blessed
it, and measured therein its sustenance”
at the end of four days, i.e., in two further days. Then the creation of the
seven heavens took two days, so the total was six days which were days with
Allah (that are not like earthly days). 

See question no. 31865. 

The words “Then
He Istawa (rose over) towards the heaven”
mean that He turned to the creation thereof. 

As-Sa‘di (may Allah have mercy on him) said: 

Then after creating the earth, He turned to the creation of
the heaven, when it was smoke that had appeared on the surface of the water.
End quote. 

Tafseer as-Sa‘di
(p. 745). 

Ibn ‘Uthaymeen (may Allah have mercy on him) said: 

With regard to the words of Allah, may He be exalted, “Then
He Istawa (rose over) towards the heaven”,
there are two interpretations among Ahl as-Sunnah. 

The first view is that what is meant is that He rose up
towards the heaven. This is the view that is regarded as more likely to be
correct by Ibn Jareer (at-Tabari), who said in his Tafseer, after
mentioning the difference of opinion:

The most likely interpretation of the words of Allah, may He
be glorified, “Then He
Istawa (rose over) towards the heaven”,
is that He rose over them and rose up, then He controlled them by His might
and created them as seven heavens. End quote. 

This was also mentioned by al-Baghawi in his Tafseer,
quoting from Ibn ‘Abbaas and most of the commentators among the earlier
generations. That is based on the apparent meaning of the word astawa
(translated here as rose over). 

Knowledge of the manner of this rising is to be referred to
Allah, may He be glorified and exalted.

The second view is that what is meant by astawa here
is intending and turning to. This view was mentioned by Ibn Katheer in his
commentary on Soorat al-Baqarah and by al-Baghawi in his commentary on
Soorat Fussilat.

Ibn Katheer said: That is, He turned to the heaven; istawa’
here conveys the meaning of intending and turning because the preposition
used here is ila (meaning to, rather than ‘ala meaning above
or over). Al-Baghawi said: That is, He turned to the creation of the heaven.
This view is not an attempt to interpret the word in a manner other than its
apparent meaning, because the verb astawa is followed by a preposition that
is indicative of purpose and aim, thus the meaning is shifted to something
that is appropriate to that preposition. Do you not see that Allah, may He
be exalted, says (interpretation of the meaning): “A
spring wherefrom the slaves of Allah will drink”
[al-Insaan 76:6]? What
is meant is that the slaves of Allah will quench their thirst thereby,
because the preposition bi (translated here as wherefrom, as opposed
to the usual min, meaning from) means that the meaning should be
shifted. So the verb should have a meaning that is appropriate to the
preposition that follows it, so that it will have a meaning that makes
sense. End quote.

Majmoo‘ Fataawa wa Rasaa’il al-‘Uthaymeen
(3/312)

With regard to the words “when
it was smoke” what is
meant by smoke here is water vapour.

Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him)
said:

This smoke is the water vapour that existed at that time, as
is mentioned in reports from the Sahaabah and Taabi‘een, and as is also the
view of the People of the Book. End quote.

Majmoo‘ al-Fataawa
(5/564)

He also said: It was said that it is the water vapour that
rose from the water over which the Throne was, for water vapour is a type of
smoke. End quote.

As-Safadiyyah
(2/76). See: Tafseer Ibn Katheer (7/166)

“and said
to it and to the earth: ‘Come both of you willingly or unwillingly.’”

Ibn Katheer said:

That is: respond to My command and comply with what I want
you to do, willingly or unwillingly. 

It was narrated that Ibn ‘Abbaas said: Allah, may He be
exalted, said to the heavens: Let My sun, My moon and My stars appear in
you. And He said to the earth: Let your rivers flow through you, and bring
forth your fruits. And they said, “ ‘We
come, willingly.’” This
view was favoured by Ibn Jareer (may Allah have mercy on him).

And he said:

“They both
said: ‘We come, willingly’
” i.e., we respond willingly to You, with all that we contain
of what You want to create of angels, humans and jinn, in obedience to You.
This was narrated by Ibn Jareer.

Al-Hasan al-Basri said: If they had refused to comply with
His command, He would have punished them with a punishment of which they
would have felt the pain. This was narrated by Ibn Abi Haatim. End quote.

Tafseer Ibn Katheer
(7/167)

As-Sa‘di said:

That is, comply with My command, willingly or unwillingly,
for My command will inevitably be executed. “They
both said: ‘We come, willingly’”
for we cannot go against Your will. End quote.

Tafseer as-Sa‘di
(p. 745)

“Then He
completed and finished from their creation (as) seven heavens in two Days”
that is, He finished shaping the seven heavens in two days, i.e., two
further days, namely Thursday and Friday.

“and He
made in each heaven its affair”
i.e., He decided and arranged for every heaven what it needs of angels and
what it contains of things that no one knows except Him.

“And We
adorned the nearest (lowest) heaven with lamps (stars)”
which are the stars that shine on the people of earth

“as well
as to guard” that is, to
protect them against the devils lest they listen to those on high.

“Such is
the Decree of Him the All-Mighty, the All-Knower”
that is, the Almighty to Whose might all things are subjected, so that He
subjugates them and subdues them, the All-Knowing Who knows the movements of
all creatures.

Tafseer Ibn Katheer
(7/167)

See also: Tafseer Ibn ‘Atiyyah (5/7); Tafseer al-Qurtubi
(15/343); Fath al-Qadeer (4/582)

And Allah knows best.