Does showing favor in matters other than charity—whether through actions or emotions—invalidate the deed and nullify its reward, similar to how showing favor invalidates charity as stated in His saying, the Almighty: "O you who have believed, do not invalidate your charities with reminders of your favor or injury"? And what is the evidence for that?

"Al-mann" (to boast about one's charity or good deeds) is the explicit or implicit mentioning of one's favor and kindness to others. It is condemned among people, whether it pertains to charity or other matters. The dispraise of al-mann and severe warnings against its perpetrator have been mentioned in the Qur'an and Sunnah (definition), and scholars have considered it among the major sins (al-kaba'ir). If al-mann invalidates charity, it also invalidates other deeds for which one boasts, because it is a major sin. Nevertheless, major sins do not nullify all good deeds, but they may invalidate the specific deed in which they are committed, or diminish all or some of its rewards. However, what nullifies all deeds is apostasy from Islam.