Whenever the Prophet (may Allah's peace and blessings be upon him) received good news, he would fall down in prostration out of gratitude to Allah

The noble Hadīth shows the attitude of the Prophet (may Allah's peace and blessings be upon him) every time he received good news or glad tidings. He used to fall down in prostration expressing gratitude to Allah, the Almighty.
Prostration of gratitude has been made permissible on the occasion of receiving a new blessing. However, it is not permissible in case of constant blessings such as the blessings of Islam, health, richness, and the like. This is because the blessings of Allah are perpetual and uninterrupted. Had prostration been made permissible for such type of constant blessings, then one would have spent his whole life in prostration. Rather, expressing gratitude for such blessings should be by worshiping and obeying Allah, the Almighty.