It is not permissible to
write the Exalted Name "Allah" and "Muhammad" (peace be upon him) parallel to each other on a paper, portrait or a wall. This act includes excessive reverence to the Messenger (peace be upon him); it also includes equality to Allah (Exalted be He), leading to a means of Shirk (associating others with Allah in His Divinity or worship). The Prophet (peace be upon him) said,
Do not (Part No. 1; Page No. 170) over praise me as the Christians did with the son of Maryam (Mary), for I am only a servant (of Allah). Therefore you should say (about me) "the Servant and Messenger of Allah."
Therefore, such portraits or papers should not be hung. Any similar writings on a wall should also be wiped out, to protect the `Aqidah (creed) and act in accordance with the recommendation of the Messenger (peace be upon him).May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.