Minimum number of people that constitutes a congregational Salah
Is the Salah (Prayer) of two persons together counted as congregational Salah or not? What is the ruling on a person who performs Salah then remembers that they did not perform Wudu' (ablution)?
If two or more people pray together, this constitutes a congregational Salah, and the greater the number of people, the greater the merit. It should be noted that one should stay committed to the duty of offering congregational Salah in the Masjid (mosque).
anyone who performs Salah, then later remembers that they have not performed Wudu', they must repeat their Salah after performing Wudu'. The Prophet (peace be upon him) said:
The Salah of any of you will not be accepted if they experience Hadath (ritual impurity that invalidates ablution) until they perform Wudu'.
(Agreed upon by Al-Bukhari and Muslim)
He (peace be upon him) also said:
Salah is not accepted without purification, nor is charity accepted out of the ill-gotten (money or property).
in his Sahih) (Part No. 7; Page No. 290) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.