Animals are routinely sacrificed on Eid ul Adha in memory of the sacrifice of _________?

Animals are routinely sacrificed on Eid ul Adha in memory of the sacrifice of _________?

قربانی کی یاد میں عید الاضحی پر جانوروں کی قربانی معمول کے مطابق کی جاتی ہے؟
Explanation

The story of Qurbani begins before Islam, with the Prophet Ibrahim (as) and his son Ismail (as). It reminds us of their strength of faith, and of God’s favour and mercy upon the believers.

Eid al-Adha is known as Festival of the Sacrifice in Islamic faith and Muslims worldwide. Eid-ul-Adha observes every year in the month of Islamic Date of ZULHIJJAH 10."