In the Name of Allaah…
‘Aqeeqah: Slaughtering sheep after the birth of a newborn, two for a boy, one for a girl, preferably on the seventh day after the birth.
Ibn Qudaamah (d.620), may Allaah have Mercy on him, said:
“The ‘aqeeqah is a Sunnah (recommended deed) according to the vast majority of the scholars, like Ibn ‘Abbaas, Ibn ‘Umar, ‘Aa’ishah, the jurists of the taabi’oon (those who came after the companions), and the scholars of the various lands, with the exception of Ahlur-Ra’y (the Hanafees), who held that it was from the customs of Jaahliyyah (the pre-Islamic period of ignorance)… And Al-Hasan (al-Basree) and Daawood (ath-Thaahiree) held it to be an obligation…” 
He went on to cite ijmaa’ (scholarly concensus) that it is recommended and not obligatory, however his quotes from the scholars who opposed this disproves any claim of concensus. 
The Order for the ‘Aqeeqah
Some narrations from the Prophet (may Allaah raise his rank and grant him peace) include or indicate directives to perform the‘aqeeqah.
Salmaan ibn ‘Aamir adh-Dhabbee (may Allaah be pleased with him) narrated that the Messenger of Allaah (may Allaah raise his rank and grant him peace) said:
مع الغلام عقيقة فأهريقوا عنه دمًا وأميطوا عنه الأذى
“Along with a newborn son is an ‘aqeeqah, so spill blood for him (i.e. slaughter sheep), and remove the harm from him (i.e. shave his hair).” 
And ‘Aa’ishah (may Allaah be pleased with her) said, “The Messenger of Allaah (may Allaah raise his rank and grant him peace) ordered us to slaughter a sheep for a newborn girl, and two sheep for a boy.” 
How the Vast Majority of Scholars Understood the Order
However, the vast majority of the scholars understood these directives to be orders of recommended guidance, when comparing them to the remaining texts on the subject.
‘Abdullaah ibn ‘Amr ibn al-‘Aas (may Allaah be pleased with him) narrated that the Messenger of Allaah (may Allaah raise his rank and grant him peace) said:
من ولد له ولد فأحب أن ينسك عنه فلينسك، عن الغلام شاتان مكافئتان وعن الجارية شاة
“Whoever has a newborn child and wants to slaughter for him, let him do so: Two sheep is sufficient for a boy, and one sheep for a girl.” 
The majority of the scholars consider this text to be a clear indication that the directives from the Messenger (may Allaah raise his rank and grant him peace) regarding the ‘aqeeqah were not absolute orders, but recommendations of guidance. 
And Allaah knows best.
Written by: Moosaa Richardson
 Al-Mughnee (13/393-394). Note: Al-Mughnee by Ibn Qudaamah is recognized by the scholars as one of the best and most comprehensive Fiqh books ever written.
 This is an example of Ibn Qudaamah’s leniency in citing scholarly concensus.
 Collected by al-Bukhaaree (5472) and others.
 An authentic hadeeth collected by at-Tirmithee (1513), Ibn Maajah (3163), and others. This is the wording of Ibn Maajah. Al-Albaanee discussed its chains and authenticated it in Irwaa’ al-Ghaleel (1166).
Note: It is also worth noting that ‘Aa’ishah is the narrator of this order, and she held that the ‘aqeeqah is not obligatory, as mentioned in the quote from Ibn Qudaamah. As a general rule, the narrator’s understanding of a hadeeth is given precedence in issues of differing. This gives further strength to the position of the majority.
 A hasan (authentic) hadeeth collected by Aboo Daawood (2842) and others. Al-Albaanee called it hasan.
 As is established in the science of Usool al-Fiqh according to the majority of the scholars: Orders are for obligations, unless there exists a qareenah saarifah (قرينة صارفة), something to bring the status of the order down to a recommendation.