Sayyiduna Anas (may Allah be pleased with him) narrates this saying of the Prophet (peace and blessings be upon him): "On the Day of Resurrection, the first thing for which a servant will be called to account is the prayer. If it is sound, all his other deeds will be sound; and if it is corrupt, all his other deeds will be corrupt."
Al-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains al-Qasim bin Uthman. Al-Bukhari (may Allah have mercy on him) said: "He has hadiths in which he is not corroborated." Ibn Hibban mentioned this narrator in al-Thiqat and said: "He sometimes made mistakes."
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 1608