It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) who says: Once I saw the Prophet (peace and blessings be upon him) relieving himself facing the Ka'bah while sitting on two unbaked bricks.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 5747
Hadith Gradingحکم دارالسلام:حديث حسن، وهذا إسناد ضعيف لضعف أيوب بن عتبة.