Sayyiduna Anas (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) said: "On the Day of Resurrection, the first thing a servant will be asked about is that his prayer will be examined. If it is sound, that servant will be successful; and if it is corrupt, that servant will be disgraced and suffer loss."
Al-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains Khulayd bin Da'laj, whom Ahmad, al-Nasa'i (may Allah have mercy on him) and al-Daraqutni (may Allah have mercy on him) declared da'if (weak). Ibn Adi (may Allah have mercy on him) said: "Most of his hadiths are corroborated by other narrators."
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 1609