'Aishah (RAA) narrated, "Allah's Messenger (ﷺ) commanded them to slaughter two sheep equal (in age) for a boy and one for a girl at their birth.' Related by At-Tirmidhi and graded it as Sahih. (ES)
English reference (ES): Book 12, Hadith 1398 (ES)
Arabic reference (ES): Book 12, Hadith 1357 (ES)