Wabarah said: I asked Ibn Umar (may Allah be pleased with them both) about a person who leaves witr until the sun rises: should he pray it? He said: What do you think, if you left the morning prayer until the sun rose, would you pray it? The narrator said: I said: Then what? He said: Then what (indeed)?
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4534