Mishkat al-Masabih 3 Purification كتاب الطهارة 74

وَعَن أُمَيْمَة بنت رقيقَة قَالَتْ: كَانَ لِلنَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَدَحٌ مِنْ عَيْدَانٍ تَحْتَ سَرِيرِهِ يَبُولُ فِيهِ بِاللَّيْلِ. رَوَاهُ أَبُو دَاوُد وَالنَّسَائِيّ

Umaima daughter of Ruqaiqa said that the Prophet had a wooden vessel under his bed in which he passed water at night. Abu Dawud and Nasa’i transmitted it.