[quote="FrDavid96, post:8, topic:199982"]
Believe it or not, this issue actually IS found in canon law; only not directly.
Under canon law, the diocese has a responsibility to provide for the needs of a priest--in other words, to support him financially.
Parents likewise have an obligation under canon law, natural law, and divine law, to provide for the needs of their children.
This means that if a priest adopts a child, he is placing a financial obligation on the diocese to provide for the needs of the child. I mention financial because it's the most obvious--the same applies to all the other obligations involved in being a parent.
Since a priest who adopts a child is actually making a commitent which obligates the diocese, he needs to have the bishop's permission beforehand.
This is not necessarily true. Secular priests do not take a vow of poverty, so if the priest were independently wealthy, there would be no financial burden on the diocese.