Sunan an Nasai
4384
Sahih+2

It was narrated that 'Asim bin Kulaib said:"I heard my father narrating from a man who said: 'We were with the Messenger of Allah two days before Al-Adha and we started to offer two Jadh ahs for one Thaniiyah, Then the Messenger of Allah said: 'A Jadh'ah is sufficient for that for which a Thaniyah is sufficient

SahihAbu Ghuddah
SahihAl-Albani