Musannaf Ibn Abi Shaybah

Hazrat Ibn Umar (may Allah be pleased with both of them) used to put a collar on his sacrificial animal and perform Ish'ar at the place of Dhul-Hulaifah.

Hazrat Urwah states that when a person sends a sacrificial animal (Hadi), he should perform the marking (Ish'ar) at the place from where he enters into Ihram.

Ibrahim says that the Companions used to perform Ish'ar on the Day of Tarwiyah (8th of Dhul-Hijjah) and even before that.

Hazrat Aswad would mark the black camel with poetry on the Day of Arafah at Arafah.

Hazrat Abu Ja'far says that I like that the camel be marked (Ish'ar) at Arafat.

Hazrat Ata and Hazrat Aswad say that one should first perform Ishaar and then tie the Ihram.

Hazrat Mujahid says that until one has entered into Ihram, one should not perform Isha'ar of the camel.