Our Hafiz Ji has told that we cannot keep our old masjid without prayers we should start prayers in old masjid or ask for mufti of Deoband they can give you right answer. We have kept a door to enter in old masjid, some of them are telling that there is no problem as we have built new Masjid we should salah prayers their only. Please give me right answer so I can do a right thing.
بسم الله الرحمن الرحيم
(Fatwa: 1384/1384/M=11/1434)
When the old mosque was going to be congested then it should be expanded as per the capacity. And if it was dilapidated then it should have been reconstructed and the expansion should have been made as per the capacity. But if you intended to construct new mosque then the old and new one should have been combined and one spacious mosque should have been erected. It is not known what the distance between both the mosques is? However, if the new and old mosques are located separated then it is wrong to leave it and not to offer salah therein, Jamah should be held therein as well.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband