“তুমি রাতকে দিনের ভেতরে প্রবেশ করাও এবং দিনকে রাতের ভেতরে প্রবেশ করিয়ে দাও। .....( 3:27).

“You cause the night to pass into the day and You cause the day to pass into the night. And You bring forth the living from the dead, and You bring forth the dead from the living. And You give sustenance to whom You choose, without stint.” 3 :27.

==Alternation of day and night :

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It is our common experience that everyday at dusk the night enters into the day and at dawn the day enters into the night, the transition being gradual. This penetration of the day into the night or vice-versa occurs on account of the following factors:i) The diurnal rotation of the earth about its own axis as ordained by Allah.ii) The spherical shape (strictly speaking oblate spheroid) of the earth and the atmosphere surrounding it, as willed by Allah.The diurnal rotation of the earth brings about the day and the night and their alternation.

This has been mentioned in verse 2 : 164 too.The round earth and its atmosphere make the merging of day and night gradual,» covering a period of time which we call twilight.During twilight a soft, mellow, diffused glow persists for sometime immediately after the sun sinks below the horizon (from sunset to nightfall) or before it rises above the horizon (from daybreak to sunrise).This phenomenon is caused by the rays of the sun that are scattered by the particles in the earth's atmosphere so that they still reach the earth ; the faint glow of twilight lasts until the sun is about 18 degrees below the horizon.

The duration of the twilight varies from place to place. Near the poles the length of twilight varies at different times of the year, but at the equator it is always about the same. The sun's path above the earth hardly varies at the equator and the length of time the sun takes to drop 18 degrees below the horizon does not vary.Twilight lasts about an hour at the equator. In the north and south of the equator the sun's path above the earth varies, causing the length of twilight to vary. During the polar summer there is a period when the sun never drops below the horizon. Just south of the arctic circle, the summer sun never drops as much as 18 degrees below the horizon. As a result twilight lasts all night from sunset to sunrise.It is also to be noted that at a particular place on the earth the twilights do not occur at the same hours of the day throughout the year.

This is caused by the annual revolution of the earth around the sun. The earth along its annual course occupies at different times different positions with respect to the sun, making the duration of day-time and night-time different. On two occasions during the year, on March 21 and Sept 23, we come across equal duration for the day and the night, whereas on June 22 the day-time is the longest and the night-time is the shortest in the northern hemisphere while on Dec 22nd the day-time is the shortest and the night-time the longest and vice versa in the southern hemisphere. Consequently, the time of appearance of twilights correspondingly varies.

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The cycle of the living and the dead :

For a rational explanation of this verse, one has to comprehend the scientific definition of the two words 'the living‘ and 'the dead'. 'The living’ stands for organisms which are themselves composed of non-living molecules but constituted into tissues with the spark of life that endows them with the capacity of carrying on all the life processes called metabolic activities. 'The dead' implies matter consisting of non-living molecules without the virtue of life activities namely nutrition and reproduction.It is Allah the Almighty Who can breathe in 'the spirit' into a collection of non-living molecules at the appropriate moment and this subject is beyond the scope of our present day knowledge.

The present discussion is mainly centered on the circulation of matter from the non-living material into the living beings for their survival and the reversion of the living to the non-living. This universal phenomenon known as ’cycle of matter' can be elaborated as follows :-Life is supported in the regions of the earth known as the biosphere which includes the oceans, the surface of the continents up to a depth, and the lowest part of the atmosphere. Plants assimilate all the constituent elements of their living matter in mineral form and convert them into the diverse organic constituents of plant tissues which in their turn serve as food for animals.

The elements that are combined in organic form in the bodies of living organisms must eventually be converted once more into inorganic form.This is the process known as mineralization of organic compounds which occurs through combustion such as forest fires and burning of organic fuels by man, through the respiratory activities of animals and plants, and most importantly, through the decomposition of plants, animals, and their organic by-products by micro-organisms that are capable of digesting and oxidizing these compounds.This flow of matter can be further elucidated by referring to some basic chemical elements that make up about 98% of the material found in living organisms. ....

Carbon :

Green plants can convert solar energy to chemical energy by a process called photosynthesis. Whenever the plants utilize this energy through respiration carbon dioxide is released again either into the air or into water. The plants are consumed by animals, and all organisms after death leave in their bodies carbon compounds accumulated during their life time.

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Water (H20) :

Animals including man may pick up water by drinking while plants absorb it from the soil. In all organisms, some water becomes chemically incorporated into living substances, later to reappear when the substances are broken down. Eventually, all water taken in by organisms returns to the atmosphere, in plants largely through the leaves, in animals through breathing or evaporation from the skin or when animals discharge their wastes.

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Nitrogen :

Nitrogenous compounds are synthesized by plants after absorbing nitrogen from nature through the help of various microbial ‘ agents or through assimilable nitrogenous compounds available in the soil. These serve as a nitrogen source for the entire animal kingdom. Unlike plants, animals do excrete a significant quantity of nitrogenous compounds in course of their metabolism in the form of ammonia, uric acid, and-as urea.

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Calcium :

Compounds of calcium are quite common in the rocks of the earth, and are picked up by animals in the dissolved state with water, Land plants obtain calcium compounds from the soil. Many kinds of animals use these in building skeletons in the form of bones or shells while the plants utilize calcium in the formation of cell wall. When animals and plants die, their skeletons and shells accumulate in the soil or on the bottom of oceans, lakes, and ponds for final disintegration

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Phosphorus :

It is assimilated by living organisms in inorganic form as phosphates. In the living cells phosphorus is incorporated into the. high energy phosphate compounds, nucleic acids etc. Upon the death of the cell, it is again liberated as inorganic phosphate by a process called hydrolysis.

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Sulphur :

It is an essential constituent of living matter in the form of amino acids, cystine, methionine, and some co~enzymes. It is abundant in the earth‘s crust and is available to living organisms principally in the form of soluble sulphates. The organic sulphur compounds synthesized by plants serve as nutrients for animals and plant micro-organisms that decompose the dead plant and animal bodies, liberating hydrogen sulphide gas into the atmosphere.

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Magnesium :

It is a part of the chlorophyll molecule in green plants and is absorbed from the soil, and later enters the living cells of the herbivorous animals through grazing. In both cases, magnesium finds its way back to the soil after the death and decay of animals and plants. ........

Trace elements :

Elements like zinc, copper, molybdenum are considered as trace elements, since they are indispensable in minute quantities in activating the specific enzymes in the living cells. These occur as contaminants of the major constituents of nutritive media, and in the dust particles from the air. The entry and exit of these also follow the same course as the essential elements mentioned above.Thus, the possible meaning of 'bringing forth the living from the dead, and the dead from the living as proclaimed in this Quranic verse, is strictly in accordance with modern scientific knowledge.***Reference 1. World Book of Encyclopaedia, Vol. 12, p. 342.