Sheikh `Abdel Khaliq H. Ash-Shareef, states: “The five daily obligatory Prayers must be performed at certain times. In the Glorious Qur’an, Allah, Most High, says: “(Salah) worship at fixed hours hath been enjoined on the believers.” (An-Nisa’: 103)
Therefore, some Muslim scholars are of the opinion that a Muslim is not permitted to make up for the missed obligatory Prayers unless there is a valid reason for missing them, such as over-sleeping. Imam Ash-Shafi`i, however, is of the opinion that whoever deliberately misses an obligatory Prayer, should make up for it in the hope that Allah will forgive him. If this is the case with regard to a person who is alive, it is unacceptable for the deceased, i.e., his relatives cannot make up for what he deliberately missed of Prayer. Nevertheless, we advise the family of the deceased, who deliberately missed some obligatory Prayers, to make Du`a’ for him and give charity on his behalf.”