Okla. Stat. tit. 58, § 58-415: Hearing of petition

If all heirs, legatees and devisees in said estate do not file

in court their written consent to such sale, the district court, at

the time and place appointed in such order or at any other time to

which the hearing may be postponed, upon satisfactory proof of

service, mailing or publication of a copy of the order to show

cause, and of posting the same, as provided in this chapter, by

affidavit or otherwise, must proceed to hear the petition, and hear

and examine the allegations and proofs of the petitioners and all

heirs, legatees and devisees of said decedent who may oppose the

application.