#What did Yahweh say would be the sin offering for the Levitical priests on the first day?

Yahweh said a bull from the cattle would be a sin offering for the Levitical priests on the first day. [43:19]

#Whose descendants would serve as the Levitical priests at this altar?

The descendants of Zadok would serve as Levitical priests at this altar. [43:19]