Thank you for your question. It depends what you mean by meditation. If it is akin to thinking (tafakkur) or watching over oneself (muraqaba) then these are practices which are condoned in Islam and indeed recommended for people seeking a spiritual life. But as for the Prophet's own states, much of that is unknown as they are states after the station of reaching. The Prophet's (saw) spiritual journey was different to most of ours as his beginning was further than where we will end up. Every station has its practice and the Prophet (saw) had states with Allah that we cannot quite imagine as we have not experienced the like of those states. Meditation in the sense that it is discussed as a spiritual or mental practice is much below these levels.
May you always be successful