Praise be to Allah, the Lord of the Worlds.

Shafie scholars have stipulated that the age of the lamb acceptable as an Udhyah (Sacrificial animal) is completing one year and starting the second, or the falling of its frontal teeth. Ar-Ramli (May Allah have mercy on him) said: "When a lamb`s teeth fall down before it reaches one year of age, then it avails as an Udhyiah." {Nehayat Al-Mohtaj}. Hanafie scholars permitted sacrificing the six-month old lamb if it looks as big as the two-year old.

It is stated in {Ad-Dur Al-Mokhtaar}: "The six-month lamb avails as a sacrifice when it looks as big as the two-year old."

Hanbali scholars stated that if the lamb completed six months, then it avails unconditionally so long as it is free of defects.

Al-Mirdawi, a Hanbali scholar, said: "Only the six-month lamb avails as an Udhyiah, and this is our Madhab and that of fellow scholars."{Al-Ensaaf}.

All of the above opinions are based on the narration in which the Prophet (Blessings and peace of Allah be upon him) said: "A lamb may be given as full payent for that for which has full-grown animal is payment." {Related by abu Dawud}.

Therefore, adherence to the two stipulations of the Hanafie and Shafie scholars is safer. However, the sacrifice of whoever followed the opinion of the Hanbali scholars avails as well. And Allah the Almighty knows best.