It is normal for people to become sad, feel grief, and mourn because of death of a person. Moreover, it is permissible for people to cry and weep silently by disclosing their pain. The Prophet Muhammad (saw) also cried in tears silently when his son Ibrahim, his daughter, and his daughter’s child died. (Bukhari, Jana’iz, 43) But, he also declared that it was not appropriate to oppose to the predestination of Allah and sob with excess behaviors as the people used to do in pre-Islamic period. However, the Prophet’s words after demise of his son at a young age constitutes an example for believers in this subject: “The eyes are shedding tears and the heart is grieved, but we will not say except what pleases our Lord. …” (Bukhari, Jana’iz, 32, 42, 43).
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS