Diskuterade detta med några systrar idag och det visade sig att jag hade fel subhanAllah må Allah förlåta mig för mina synder..

Some people have told me that the prohet saw said that between every 2 adhans ie. the second adhan being the iqamah there is a prayer for the one who wishes.
if the hadith is authentic then why is there no nafl prayer before the fardh of maghrib.

Answer:

In the name of Allah Most compassionate Merciful

The actual hadith which excludes the magrib prayer is as mentioned in Imdad al-Fattah as follows:

It is disliked to perform the nafl before the fard of magrib. It is mentioned in Mi'raj al-dirayah: One cannot perform nafl before magrib because of the words of the Prophet (Allah bless him and give him peace), 'between the two adhan one can perform any salah except Magrib.'(Tabrani has documented this hadith in Awsat) Khattabi said, 'two adhans mean the iqamah and adhan.' [Imdad al-Fattah Sharh Nur al-Idah, pg 187]

However this hadith is mentioned without the exception and restriction (qayd) too in Bukhari as follows:

It has been reported by Abdullah ibn Mughaffal, he said, the Prophet (Allah bless him and give him peace) said, 'Between the two adhan one can perform any salah'... 'between the two adhan one can perform any salah' then he said the third time...'for the one who wishes.'
It has been reported in Bukhari. [Imam Zafar Ahmad Usmani, I'la al-Sunan, pg 16 V.7]

And Allah alone knows best

Ilyas Patel

Faraz Rabbani adds:

Imam Ibn Abidin quotes a number of classical authorities mentioning that praying supererogatory prayers before the Maghrib prayer was not from the practice of the Four Khalifas, nor the Ten Promised Paradise, nor the leading Companions of the Prophet (peace and blessings be upon him). Thus, Ibn Umar (Allah be pleased with him) and other Companions themselves understood that this was only a sunna for a limited time-period, until the command of performing Maghrib prayer without delay was legislated. After this, the previous recommended sunna of praying 2 rakats before Maghrib prayer was abrogated. [ Ibn Abidin, Radd al-Muhtar ]