Why didn't Al-Dahhak clarify the truth to the Christian instead of lying to him by telling him that Islam does not prohibit alcohol, and explain to him that Islam admits him to Paradise, and that drinking alcohol will not expel him from the faith?

Ibn al-Jawzi mentioned that a Christian used to frequent Al-Dahhak bin Muzahim. When Al-Dahhak asked him, "Why do you not embrace Islam?" The Christian replied that he loved wine and could not abstain from it. Al-Dahhak then said to him, "Then embrace Islam and drink it." So, the man embraced Islam. Al-Dahhak then told him, "You have now embraced Islam. If you drink, we will apply the hadd punishment to you, and if you apostatize from Islam, we will kill you." If this story is authentic, then it is presumed that Al-Dahhak did not lie to the Christian. Rather, he intended to tell him that his embracing Islam while drinking wine was less severe than his remaining in disbelief, or perhaps he used ambiguous statements, seeing in that an interest in the man embracing Islam.