Jarir bin Abdullah (May Allah be pleased with him) said:
The Prophet ﷺ said, "When the slave runs away from his master, his Salat (prayer) will not be accepted."

[Muslim].

Another narration is: "He is guilty of disbelief (i.e., in case he believes in the lawfulness of doing so)."

وعنه عن النبي ﷺ : "إذا أبق العبد، لم تقبل له صلاة " ((رواه مسلم)) . وفي رواية: "فقد كفر " .