Abdullah bin Muhayriz reports from a man of Banu Kinanah, who says: I heard Ubadah bin al-Samit (may Allah be pleased with him) say: I heard the Messenger of Allah (peace and blessings be upon him) say: "Five prayers Allah Almighty has prescribed upon His servants. Whoever fulfils them and does not neglect them has a covenant with Allah that He will forgive him and admit him into Paradise.
And whoever does not fulfil them, treating their right lightly, has no covenant with Allah: if He wills He will punish him, and if He wills He will forgive him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 1692