Wa`alaykum as-salam wa rahmatullahi wa barakatuh.

 

It is important for him to attend the prayer in congregation at the mosque – if he can do so without difficulty.

However, he is allowed to lead his family in the same prayer before or after praying at the mosque.

We learn from the traditions that Mu`adh ibn Jabal, one of the eminent companions of the Prophet (peace be upon him) used to pray with the Prophet in the congregation and then head towards Quba to lead the people in salah for the same prayer.