Muwatta Malik 40
Mauquf Sahih Graded by Salim al-Hilali Book of Purity · Hadith 40 of 1,858وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ ابْنَ عُمَرَ، كَانَ يَنَامُ جَالِسًا ثُمَّ يُصَلِّي وَلاَ يَتَوَضَّأُ .
Yahya related to me from Malik from Nafithat Ibn Umar used to sleep sitting and then would pray without doing wudu
References
Muwatta Malik 40
In-book: Book 2, Hadith 9 Source: hadith-api (fawazahmed0)