It is narrated from Sayyiduna Jundab bin Sufyan al-Alaqi (may Allah be pleased with him) that he (peace and blessings be upon him) said: "Whoever offers the morning prayer is under the protection of Allah. So look, O son of Adam, lest Allah demand from you anything concerning His protection."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2179