Reference: Siyar A’laam an-Nubalaa v11 p177
Ibraaheem al-Harbee رحمه الله said that was asked about [the permissibility of] a Muslim saying أَكْرَمَكَ الله (may Allaah honour you) to a Christian. He said:
‘Yes, [and] he should intend by it [his embracing] Islaam.’
