Sayyiduna Abdullah bin Mughaffal (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) said three times: "Between the adhan and the iqamah there is a prayer." The third time he said: "It is for whoever wishes."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4489