Is it permissible to eat from the designated Udhiyah before Eid? And is the Udhiyah for the deceased considered Sadaqah (charity) and not Udhiyah?

The Udhiyah (sacrifice) is a confirmed Sunnah for those who are able, and it is recommended to eat from it, give some as a gift, and give some in charity. The Prophet, peace be upon him, would not eat on the day of Eid al-Adha until he returned and ate from his sacrifice. He said concerning the meat of the sacrifices: "Eat, store, and give in charity."

As for offering the Udhiyah on behalf of the deceased, there is a difference of opinion regarding it, but the preponderant view, in our opinion, is its permissibility.