The Wisdom Behind Shorth Soorahs:
The Makkan soorahs (chapters) usually had short verses, catchy rhymes, and very strong rhythm. These qualities were meant to catch the attention of the listeners who were opposed to the message of Islaam.

The verses had to be short because the audience would not be willing to listen to long, drawn out statements. As soon as they heard any of the Qur’aan, they would stick their fingers in their ears and turn away. Thus, the verses had to strike home immediately. The meanings were very clear whereas the oracles and chants of the fortunetellers were mostly onscure and vague.

The Wisdom Behind Long Soorahs:
The Medeenan verses tended to be longer than those of Makkah. In fact there are a number of Madeenan verses which are longer than whole soorahs (chapters) of the Makkan peroid. The longest verse of the Qur’aan is the verse on loans in the Madeenan soorah, Al-Baqarah (2:282). The shortest soorah of the Qur’aan is the Makkan soorah, Al-Kawthar (Ch. 108), which contains a total of only 11 seperate words in three short verses.

The need to catch the attention of unwilling listeners was no longer there, because Islaam had become strong and its followers were many. Thus, the audience at this stage was quite willing to listen attentively to longer verses teaching the vital laws of Islaam.

[Taken from ‘Usool At-Tafseer, p. 210 & 214]

One benefit gained from understanding this is to know a bit about the person to whom you are giving da’wah to. If you’re giving da’wah to a brother who is already established himself on deen, then ulhumdulillaah you can speak to him longer.

If however, you are speaking (giving da’wah) to an individual who is not on deen, then you would need to be concise and short in your speech. I remember, before I was practising, my mind used to switch off after about 3/4 mins when being given da’wah. I also remember about 5 years ago when I started practising, I was in Madeenah, walking back to my hotel, and I had a brother speaking to me about the deen, and within about a coulpe of mins my mind was switched off.

So know, O Da’ee’s, that giving da’wah needs wisdom…