My question is that I read in Bahishti Zewar of Maulana Ashraf Ali Thanwi r.a. that if any Muslim utters kufr or kufr word then all his Ibadat and pious deed when he was a Muslim will rendered null and void if he had performed a fardh hajj it will also rendered null and void. So he has to renew all pious deeds. So my question is that I have used once kufr word so I have to make qaza of all my salah.
بسم الله الرحمن الرحيم
(Fatwa: 823/841/SD=9/1438)
If a Muslim uttered some kufriya word jokingly then after making taubah it is not mandatory for him to make the qaza of his all previous salah. Thus if you sometimes uttered some kufriya word then it is not necessary for you to make qaza of all the previous salah. What you read in Bahishti Zewar write its complete reference.
(وما أدى منها في يبطل ، ولا يقضي) من العبادات (إلا الحج) لأنه بالردة صار كالكافر الأصلى ، فإذا أسلم وهو غني فعليه الحج فقط . (رد المحتار على الدر المختار 302/3 ط إحياء التراث)
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband