Praise be to Allaah.
We do not know of any evidence (daleel) to suggest that it is prescribed in sharee’ah to kiss it, but if a person does so, there is nothing wrong with that. It was narrated that the great Sahaabi ‘Ikrimah ibn Abi Jahl used to kiss the Mus-haf and say, “This is the word of my Lord.” Whatever the case, there is nothing wrong with kissing it, but it is not prescribed to do so and there is nothing to indicate that it is prescribed in sharee’ah. But if a person kisses it as an act of veneration and respect if it falls from his hand or from a high place, there is nothing wrong with that, in sha Allaah.
Fataawa wa Maqaalaat Mutanawwi’ah li Samaahat al-Shaykh al-‘Allaamah ‘Abd al-‘Azeez ibn ‘Abd-Allaah ibn Baaz (may Allaah have mercy on him), vol. 9, p. 289