The Noble Qur’ an has introduced itself as “ the clarification for all things” in Surah an-Nahl: 89. The heavenly word of God is recognized among Muslims by various names, one of which is “ Furqan” [the criterion] that means the decisive factor between good and evil representing all jurisprudential, religious, legal, individual, and social rules. Sometimes thoroughly and sometimes briefly, the Holy Qur’ an has declared relative Ahkam (arbitrations) for inheritance, Hudud (certain penalties), Defense, Jihad (war), Zakat and Khums (donation of wealth), marriage, and so on. Islamic researchers with regard to their own interest, expertise, and capabilities in each specialty have delved deep into the endless ocean of physical and metaphysical sciences in the Qur’ an. Using speech-act-theory, many Qur’ anic researchers have conducted valuable interdisciplinary studies in this regard. This article aims to introduce the speech-act-theory and one of its divisions called “ declarative speech act” in the relative chapters and verses about the battles of Prophet Muhammad (PBUH). Using descriptive analysis and library method, the authors of this paper have attempted to collect data from various outstanding resource books such as The History of Islam, The Biography of the Prophet Muhammad (PBUH), Maghazi (Accounts of the Prophet’ s Battles), translations and exegeses of the Qur’ an. The results of the study showed that the function of declarative speech acts with their various frequency in the Holy Qur’ an is to proclaim the divine will of God (Ahkam).