Mutual Relationship

These two surahs form a pair as regards the subject discussed in them. However, the style of the first surah is predominantly argumentative while that of the the second sentimental -- sentimental in the sense that there exists a strong element of appeal to invoke the mercy of the Almighty. Both are addressed to the Prophet (sws) and it is evident from the subject discussed in them that they were revealed, after the Prophet’s migration, in Medinah when beholding the success of the Prophet's mission, the Jews and the Quraish as well as the progeny of Satan both in the jinn and in men were preparing to launch an offensive against him.   

Central Theme

The central theme of both the surahs is to advise and counsel the Prophet (sws) to seek protection and refuge of the Almighty from all the calamities of the world and from the evil of everything created by the Almighty because it is He alone who can actually give refuge to man from all evils and calamities.

Relationship with Beginning of the Qur'an

These closing surahs of the Quran, from their very subject, direct the attention of every keen reader to Surah Faatihah, the opening surah of the Quran, in which a person acknowledges the Tauheed of Allah and prays to the Him to show him the right path. The Quran is actually a reply to this prayer as it explains this right path; it reaches its completion through the most comprehensive expression of Tauheed in Surah Ikhlaas. Once a person reaches the end of the Quran, he raises his hands in prayer to seek protection of the Almighty through these two surahs from every waylayer present on the path of Tauheed and from the difficulties he is bound to encounter while treading this path.

Explanation

Surah Falaq

In the name of Allah, the Most Gracious, the Ever Merciful

Pray ye [O Prophet!]: I seek refuge with the Lord who breaks apart and brings forth everything1; from the evil of all that He has created2 and [especially] from the evil of darkness when it overspreads3, and from the evil of those who blow upon knots4 and from the evil of every envious creature when it envies5.

Surah Nās

In the name of Allah, the Most Gracious, the Ever Merciful

Pray ye [O Prophet!]: I seek refuge with the Cherisher of mankind, the King of mankind, the God of mankind6 from the evil of the Prompter [of vice] who withdraws [after his prompting]7, who prompts evil suggestions in the hearts of men, [and is] from among the jinn and mankind.

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1. Every act of creation is preceded by a process of breaking apart and as such the verse refers to the tremendous process of creation going on in this universe. It is the Almighty who brings forth the dawn from the night, the sprout from the seed, the child from the womb and the springs from the mountains.

2. The verse cites the reason for seeking the refuge of the Almighty: since Allah is the Creator of all, it is only befitting to ask refuge from the evils of the entities created by Him. No other being whosoever can be in a better position to give protection in this regard than the Creator Himself.

3. With this verse begins a mention of three specific spheres in which the onslaught of evil must be warded off by seeking the Almighty's refuge. Suffice to say that the evils in store for man in the shrouds of darkness are multifarious. It is only with the help of Allah that they can be encountered.  

4. That is from the evil of magicians and charmers who have always existed in the Jews.

5. An envious being, whether from the jinn or from men, is very lethal. It is his intense desire to harm the person he envies in whatever way possible.

6. These opening verses of the surah which repeatedly address the Almighty through His various attributes give it an emotional touch. Since these attributes are directly related to man, the appeal generated as a result is very effective.

7. Though it has not been stated in words, yet it is quite evident from the attributes mentioned and referred to later that it is Satan who is being talked about here. The verse describes Satan's technique and his line of attack: he allures people through wicked suggestions and after entrapping them, he acquits himself of all the consequences. It is also evident from this verse that Satan's only weapon is implanting evil suggestions. Apart from this, he has no other powers through which he might necessarily lead a person astray.