Abd al-Rahman bin Sabit (may Allah have mercy on him) says that the Prophet (peace and blessings be upon him) and his Companions (may Allah be pleased with them) used to slaughter camels with the left (foreleg) tied, standing on their remaining legs.
The hadith of Ibn Jurayj from Abu al-Zubayr from Jabir is mawsul (connected), and his hadith from Abd al-Rahman bin Sabit is mursal.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10219