It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When the Iqamah for prayer is called (i.e., the Takbir), then there is no prayer except the obligatory prayer." Imam Darimi (may Allah have mercy on him) said: If one is praying at home and the Iqamah is called in the mosque, then this is relatively easier.