يُصَلِّي مَعَهُمْ وَ يَجْعَلُهَا الْفَرِيضَةَ.
“I once asked abu ’Abd Allah (a.s.), about a man who performs Salah (prayer) alone then finds a congregation. He (the Imam) said, ’He can perform Salah (prayer) with them and make it to be an obligatory one.”’