Cutting off the voluntary prayer when the iqamah is called

Question:
He says: Honorable Shaykh, may Allah grant you success. You mentioned the saying of the Prophet (peace and blessings be upon him) that the takbir is what makes the prayer forbidden [to interrupt] and the taslim is what makes it permissible [to leave]. So if a person is in the sunnah of entering the mosque and the iqamah is called, does he say the taslim and break off the prayer, or what does he do?

Answer:
The Prophet (peace and blessings be upon him) said: If he is at the beginning of the prayer, he breaks it off. But if he is at the end of it, in the tashahhud or in the final prostration, he completes it. If he is at the end, he completes it; but if he is at the beginning, he breaks it off. Also, it is not permissible for him to say takbir in a voluntary prayer while the imam is calling the iqamah for the prayer; this is forbidden. Yes.