Answer
(Fatwa: 510/510-1429)
In the abovementioned question, because of uttering heathen word your wife became out of your marriage. It is in Fatwa Hindia:
يكفر إذا وصف الله تعالي بما لايليق به أو إلی الجهل أو العجز أو النقص
After that, before renewal the Eiman and nikah, both of you (husband and wife) have committed fornication by having physical relation. Both of you should do taubah from this major sin (adultery). It is essential for your wife to do taubah from the heathen word and renew her Eiman. And then, both of you should conduct nikah again in presence of two legal witnesses.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband