Hadith 2190
Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Noble Prophet (peace and blessings be upon him) said: "When the muezzin begins to pronounce the iqamah, then (after that) only the obligatory prayer can be performed."
Hadith 2191
Sayyiduna Abdullah bin Sarjis (may Allah be pleased with him) narrates: A man entered the mosque after the iqamah had been pronounced while the Prophet Muhammad (peace and blessings be upon him) was performing the prayer. This man performed two rak‘ahs and then joined the row. When the Prophet (peace and blessings be upon him) had completed the prayer, he asked: Which of the two have you counted? (The narrator is in doubt, perhaps these are the words:) Through which of the two do you hope for reward now? The prayer which you performed with us, or the prayer which you performed alone?