Ibn al-Mubarak and Abu Usamah (may Allah have mercy on them both) narrate from Kahmas (may Allah have mercy on him): "Between the adhan and the iqamah there is a prayer," and the third time he said: "It is for whoever wishes." The narrator said that Ibn Buraydah (may Allah have mercy on him) used to offer two rak'ahs before Maghrib, as in the previous narration.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4494