Is it permissible for the da'iyah (caller to Islam) to be harsh in his speech at times?

The questioner : In a hadith in Sahih Muslim, regarding the owner of the ring, and that the Prophet (peace and blessings be upon him) took it from his hand.

The Shaykh : Yes, what is it?

The questioner : That the Prophet (peace and blessings be upon him) turned his face away from al-Fadl.

The Shaykh : Al-Fadl, al-Fadl.

The questioner : Yes, some students of knowledge have cited evidence that the caller to Allah may, at times, be harsh in his calling to Allah. They gave as an example a man who is known not to be blessed and does not respect the blessing of speech; for instance, he lights a cigarette in front of him. They said it is permissible at times for him to stand up, or to cut him off, or to speak to him harshly. Is this a sound opinion?

The Shaykh : Yes, you do not turn your face away in every situation; every situation has its own appropriate response.

The questioner : I mean, the default is...

The Shaykh : The stubborn person whom we know to be stubborn, and we have authority over, we deal with him using the stronger approach. And the person who does not know, meaning we do not know that he is stubborn, we deal with him using the lighter approach. So the Bedouin urinated in the mosque, and the people rebuked him, and the Messenger (peace and blessings be upon him) stopped them. And the man spoke loudly in prayer and repeated his speech, and the Prophet (peace and blessings be upon him) did not rebuke him.