Dear Shaikh, Could you please tell me on what occasion were the below Aayaat revealed : “Say: ‘Was it at Allaah, and His Ayaat (proofs, evidences, verses, lessons, signs, revelations, etc.) and His Messenger that you were mocking?’ Make no excuse; YOU DISBELIEVED AFTER YOU HAD BELIEVED.” [al-Tawbah 9:65-66] Jazaak Allaahu Khairan

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

Allaah Says (what means): {If you ask them (about this), they declare: "We were only talking idly and joking." Say: "Was it at Allaah and His Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.) and His Messenger () that you were mocking?"   Make no excuse; you have disbelieved after you had believed.} [Quran 9:65-66].

The interpreters of the meaning of the Quran stated many reasons for the revelation of the above verses. The most famous of these statements is what is reported from Ibn 'Umar that during the battle of Tabook a man said: "I did not see more ravenous eaters, more liars, and more coward people than these recitors of the Quran. So, a man (who was sitting with him) in the praying area stood up and said to him: "You are telling a lie, and you are a hypocrite. I will definitely inform the Prophet . He informed the Prophet and then the above verse was revealed." 

Allaah Knows best.