can a brother due to personal obligation leave the lodge before a meeting is completed

A member of a lodge possesses the explicit prerogative of entering and retiring during a meeting 1. While a Mason has a duty to attend lodge and yield obedience to the Master, Masonic jurisprudence recognizes that membership rights include the freedom to enter and leave, balancing a member's lodge duties with his personal prerogatives 1. The laws and regulations of the Craft are structured to guarantee that no officer or set of circumstances interferes with a member's individual freedom to act 1.

This prerogative to retire during a session is distinct from demitting, which refers to a member's voluntary resignation of his lodge membership entirely rather than leaving a single meeting before its close 1.