Study of Zipf's Law in the Qur ān's Sūrat al-Aḥzāb and Sūrat Al-Ghāfir

The relation between the variants of the frequency and the length of the word is among the laws that George Kinsley Zipf discovered, according to which, the longer is the length of a word, the less is the frequency of its application in the text. It is tried in the present research to examine this law, which has not been so far examined on the Arabic language of the Qur’ān, with a concentration on the noun words in the Makkī and Madanī sūras of Al-Aḥzāb and Al-Ghāfir. The findings indicate that the exception of Zipf’s law, according to which the words that have less than three phonemes have less frequency in the text, is true for the sūras of Al-Aḥzāb and Al-Ghāfir. Both of the sūras follow Zipf’s law in regard to the words of 3, 6, 7, 9, 10, 11, 12, and 13 phonemes. However, these sūras violate Zipf’s law in three instances. The first instance of the violation of this law was observed in sūras of Al-Aḥzāb and Al-Ghāfir, in which the four-phoneme words had more frequency of occurrence than the three-phoneme words and one of its reasons was the repetition of four-phoneme noun words such as ayyu, kullu, and shay’ in Sūrat Al-Aḥzāb; and rabb and yawm in Sūrat Al-Ghāfir. The second instance of violation of the law was the high frequency of five-phoneme words in comparison not only to four- and three-phoneme words, but also to the length of all the words in sūras of Al-Aḥzāb and Al-Ghāfir. Among the reasons for the high frequency of five-phoneme words can be the frequent repetition of these words (such as the glorious words of Allah, rasūl, and nabī) as well as the melodious tone of the Qur’ān. The third instance of violating the Zipf law in Sūrat Al-Ghāfir concerns the eight-phoneme words, as these words have more frequency than the seven-phoneme words. As one of the reasons for the high frequency of the eight-phoneme words can one refer to the repetition of the noun words of mu’mināt, kāfirīna, and Ṣādiqīna.