Is it permissible to change the intention from Udhiyah to Aqiqah two weeks before Udhiyah, for one who has not performed Aqiqah for his children?

Changing the intention from an 'aqiqa (sacrificial animal for a newborn) to an udhiyah (sacrificial animal for Eid al-Adha) after paying part of the price and before purchasing the animal is permissible. This is because the udhiyah does not become obligatory until the sheep is designated or by vow. However, if the intention is changed after the purchase, its ruling depends on the differing opinions of scholars regarding the designation of the udhiyah merely by the intention accompanying the purchase.