Musnad Ahmad 834:15

'Abd al-Samad and 'Affan narrated to us, they said: Hammad ibn Salamah narrated to us, from al-Jurayri—'Affan said in his narration: al-Jurayri informed us—from Abu Na'amah, that 'Abdullah ibn Mughaffal heard his son saying: "O Allah, I ask You for the white palace on the right side of Paradise when I enter it." He said: "O my son, ask Allah for Paradise and seek refuge in Him from the Fire, for I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'There will be a people who will transgress in supplication and in purification.'"