Is it better to perform the pre-prayer voluntary (Sunnah Ratibah) prayer at home or in the mosque? And does one receive the reward for praying at home if it is performed in the mosque? And is it permissible to pray تحية المسجد (greeting the mosque prayer) with the intention of it being the Sunnah Ratibah?

Praying supererogatory (Nawafil) prayers at home is better than performing them in the mosque, due to the Prophet's (peace be upon him) saying: "You should pray in your homes, for the best of a man's prayer is in his home, except for the obligatory prayer." One can combine the virtue of arriving early at the mosque with performing the regular (Ratibah) supererogatory prayers at home by praying at home after the time for the obligatory prayer has begun, and then going to the mosque. As for "not being sufficient" ( عدم الإجزاء), it means that the act was not performed in the required manner, whereas "not being permissible" ( عدم الجواز) means it is forbidden and prohibited by religious law.