Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Noble Prophet (peace and blessings be upon him) said: "When any person wakes up from sleep, he should wash both his hands before performing ablution, because he does not know where his hand spent the night."
Hadith Referenceصحیح ابن حبان / كتاب الطهارة / 1063
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح: خ - المصدر نفسه.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح.