When is a voluntary prayer cut off when the obligatory prayer is established?

The questioner : When... when does the follower leave the prayer when the prayer is established?

The Shaykh : When what?

The questioner : When does the follower cut off his prayer when the prayer is established?

The Shaykh : Did you not hear?

The questioner : ... when the prayer is established ... the imam entered.

The Shaykh : No, when the prayer is established.

The questioner : ... O Shaykh ... .

The Shaykh : When it is established, this is a hadith, the wording of the hadith.

The questioner : ... the correct view is that ... .

The Shaykh : That when it is established, meaning when the iqamah begins, yes?