It is narrated from Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) that the prayer was changed through three stages. He narrated the hadith of the dream of Sayyiduna Abdullah bin Zayd (may Allah be pleased with him) and mentioned the adhan twice each, then at the end of the adhan he said: 'Allahu akbar, Allahu akbar, la ilaha illallah' (Allah is the Greatest, Allah is the Greatest, there is no god but Allah). Then he paused for a little while, then stood and said the like of it, except that he added the words 'Qad qamat al-salah, qad qamat al-salah' (The prayer has been established, the prayer has been established).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 1976