(a) Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: None of you should leave any share of his prayer for Satan, that is, by turning away only to the right; rather, he should turn to the left as well. I have seen the Messenger of Allah (peace and blessings be upon him) many times turning away from the left side.
(b) Umarah (may Allah have mercy on him) narrates: After hearing this hadith I came to Madinah and saw the dwellings of the Prophet (peace and blessings be upon him); they were on his left side.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3611