بسم الله الرحمن الرحيم
Is it from the sunnah to pray two units of prayer between the Adhaan and Iqaamah of Maghrib?
Yes, it is from the sunnah to pray two units before Maghrib; ie between the adhaan and between the iqaamah, for indeed the Messenger -صلى الله عليه و سلم- ordered with it 3 times in an authentic hadith:
“Pray before maghrib, pray before maghrib, pray before maghrib for whoever wills”(1)
His statement “for whoever wills” indicates his -صلى الله عليه و سلم- disliking that the people take it as a Sunnah; ie as a regularly established Sunnah, so praying two units before Maghrib; ie between the adhaan and iqaamah is a sunnah, however it is not a regularly established sunnah.
So it is not befitting to be performed all the time; in contrast to the regular sunnah prayers such as those before Fajr, Dhuhr and Isha, which are prayed consistently except when one is travelling, when it is from the sunnah to not pray any of the regularly performed sunnah prayers of Dhuhr, Maghrib or Isha.
The Messenger of Allah -صلى الله عليه و سلم- said
“Between every two adhaans is a prayer” (2)
Ie between the adhaan and iqaamah is a superogatory prayer, however for Fajr and Dhuhr it is regularly performed and for Asr, Maghrib and Isha it is not regularly performed.
Shaykh Muhammad Al-Uthaymeen’s
Majmoo’ rasaail wa fataawa
(1) Bukhaari and Muslim
(2) Bukhaari and Muslim