Surely you are wrong in what you are doing. You must pray Isha with the congregation even if they pray it immediately after the Athan. You must not postpone it until the middle of the night unless you are a woman or you are with a congregation in another masjid.

In the musalah near by my house salatul Isha is offered in congregation. But there is a hadeeth of RasoolAllah salallaahu alayhi wassalam that he said the best time to pray isha is nisful layl?So I end up not going to congregation for Isha. I stay at home expectingto pray at the best time. Am I doing something correct in accordance with the Quran and the sunnah and the understanding of the Salafus-Salih? I sometimes neglect praying in congregation where I get thoughts telling me It will take up some time and what not. The musalah is nearby 5 minute walk. Also a good student of knowledge said that the most reward in the salah is being there before the imaam goes into takbiratul ihraam? Is this correct?

Prayer |