What is the ruling on offering the Aqiqah on the first day of birth, and what is the ruling on the newborn's grandfather paying its cost, even though the newborn's father is able to pay for it?

The original ruling is that the 'Aqiqah is slaughtered on the seventh day, based on the Prophet's (peace be upon him) saying: "Every child is mortgaged by its 'Aqiqah; it is slaughtered for him on the seventh day, he is named, and his head is shaved." However, if a person hastens and slaughters it before the seventh day, it is permissible because he slaughtered it after its cause came into existence, which is the birth. This is similar to giving out expiation before breaking an oath.