Abd al-Rahman bin Awf (may Allah be pleased with him) said: We used to pray these two rak'ahs when we stood between the adhan and the iqamah at Maghrib.
(b) In al-Sukkari's narration it is: when we stood, meaning between the adhan and the iqamah at Maghrib.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4499