You said that: “You will not be sinful by not reciting the Du’aa-e-Qunoot” in response to whether or not one would be sinful by not reciting Dua-e-Qunoot in Witr Salah. The Imam at my local mosque has taken objection to this, stating that reciting Dua-e-Qunoot in Witr is Waajib and to deliberately leave out a Wajib would be considered sinful and hence any person who does not recite Dua-e-Qunoot in Witr Salah is sinful. He has asked you to kindly provide Daleel for your fatwa. He wants to know why you said one wouldn’t be sinful by not reciting Dua-e-Qunoot.
There are two issues here;
1. One is reciting any du’aa in Witr Salaat. The obligation will be fulfilled through that.
2. Secondly, it is not compulsory to recite the famous Du’aa-e-Qunoot, ?Allaahumma innaa nasta?eenuka?? It is sunnat to do so. If one recites, for example, ?rabbanaa aatinaa..? the obligation will still be fulfilled. (Shaami vol.1 pg.468; Qadeemi)
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai