Sayyiduna Abu Bakr (may Allah be pleased with him) says: I went to the mosque and found the Prophet (peace and blessings of Allah be upon him) standing in prayer. He says that he performed ruku‘ outside the row and then moved towards the row. When the Messenger of Allah (peace and blessings of Allah be upon him) finished, he said: "May Allah increase your eagerness, but do not do this again."
Related hadith on this topic