It wasnarrated that 'Aishah said:
"When the Prophet (ﷺ) prayed thetwo (Sunnah) Rak'ah of Fajr, he would lie down on his right side." (JA)
English reference (JA): Vol. 1, Book 5, Hadith 1198 (JA)
Arabic reference (JA): Book 5, Hadith 1254 (JA)