Rule 16 of CPC : Rule 16: When they may depart.

Explanation using Example

Example 1:

Ravi is summoned as a witness in a civil case involving a property dispute between two parties, Asha and Bharat. The court directs Ravi to attend each hearing until the case is resolved. Ravi attends the first hearing, but he has a family emergency and requests the court to excuse him from the next hearing. The court considers his request and allows him to miss the next hearing, but instructs him to attend all subsequent hearings until the case is concluded.

Example 2:

Sunita is summoned as a witness in a breach of contract case. She attends the first hearing, but the case is adjourned to a later date. The plaintiff, Rajesh, applies to the court to ensure Sunita's attendance at the next hearing. Rajesh deposits the necessary expenses with the court, and the court requires Sunita to furnish security to guarantee her attendance at the next hearing. Sunita fails to provide the security, so the court orders her to be detained in civil prison until the next hearing to ensure her presence.