Thank you for your question.
The Noble Qur'an, being the final word of the
Ever-Knowing God to mankind, is a glimpse of His
infinite knowledge. Every word, expression, or
chapter is so meticulously chosen and phrased such
as to give the utmost precision of meaning, as well
as splendid eloquence and deep impact.
The words: "East" and "West" have been mentioned in
the Qur'an using the three Arabic morphological
forms — single, dual, and plural — in each case to
purposely give a specific meaning.
In the singular form, reference is often to the
geographic east and west directions of the planet
Earth, as in the following verse, when Allah says
what means:
*{It is not righteousness that you turn your faces
to the East and the West; but righteous is he who
believes in Allah and the Last Day and the angels
and the Scripture and the Prophets; and gives his
wealth, for love of Him, to kinsfolk and to orphans
and to the needy and to the wayfarer and to those
who ask, and to set slaves free; and observes proper
worship and pays the poor due (zakah).
And those who keep their treaty
when they make one, and the patient in tribulation
and adversity and time of stress. Such are
they who are sincere. Such are the God fearing.}*
(Al-Baqarah 2:177)
Also, the singular form could refer to the
alternation of the sun rising and setting, by which
the day and night alternate to maintain life on
earth, as in the following verse, when God says what
means:
*{...Ibrahim (Abraham) said, "Yet surely Allah
brings the sun from the East, so come bring it from
the West." Then the one who disbelieved was
confounded; and Allah does not guide the unjust
people...}* (Al-Baqarah 2:258)
Alternatively, the combined expression "East and
West" is used to express the domination of Allah
over the whole earth, albeit the whole of creation.
Examples of this usage can be read in the following
verses, when God says what means:
*{And Allah has the East and the West...}* (Al-Baqarah
2:115)
*{...Say, "To Allah (belong) the East and West;" He
guides whomever He decides to a straight Path...}*
(Al-Baqarah 2:142)
On the other hand, the dual form, used in other
verses, could refer to either of two meanings:
The first is the separate rising and setting of the
sun and the moon, both of which were and are the
basis for defining the time units. This is along
with the solar and lunar calendars. An example for
this is the verse that says what means:
*{The Lord of the two easts and the Lord of the two
wests.}*
(Ar-Rahman 55:17)
The second is the two extreme points of earliest
sunrise and latest sunrise, along any latitude of
the globe in any one day (this is explained in the
fourth point of the "plural" meanings below). An
example of the Qur'anic mentioning of this meaning
is the verse that says what means:
*{Until, when he comes to Us,
he says, "Oh, would that there had been between me
and you the distance of the two easts!"}*
(Az-Zukhruf 43:38)
Coming to the plural forms of "Easts" and "Wests,"
they were used in the verses which say what means:
*{The Lord of the heavens and the earth, and
whatever is between them both and the Lord of the
Easts.}* (As-Saffat 37:5)
*{Yet no, I swear by The
Lord of the Easts and the Wests; surely We are
indeed (the) Determiners.}* (Al-Ma`arij 70:40)
In these verses, the plural forms could carry a
number of physically significant meanings. They
could refer to either or all of the following
phenomena:
-
The "apparent" rising and setting of each of the
celestial bodies relative to the earth, due to
the rotation of the earth around its own axis
and around the sun.
-
The different (consecutive) times of sunrise or
sunset as we move around the globe from east to
west along any latitude (time zones).
-
The variable times of sunrise and sunset in the
same location around the four seasons; and hence
the variation in the length of daytime between
summer and winter. This variation widens as we
move towards the poles from the equator.
-
As the axis of rotation of the earth around
itself is inclined to its axis of rotation
around the sun, the time of sunrise differs (in
the same day) along the same longitude as we
move to higher or lower latitudes.
From this last fact, it follows that in any one day,
all year round, there are oppositely two extreme
latitudes (north and
south): one with the earliest time of sunrise and
the other with the latest. This explains the
Qur'anic use of the dual form pointed to above.
I hope this clarifies the wise and precise
linguistic usage of the same word (east or
west) in different morphological forms
(singular, dual, or plural). In fact, it could
exactly fit several physical phenomena of this
marvelous creation of the Ever-Knowing
Ever-Determiner Allah.
Thank you and please keep in touch.