16:102
Say, the Holy Spirit has brought the revelation from thy Lord in Truth, in order to strengthen those who believe, and as a Guide and Glad Tidings to Muslims.
Most classical commentators interpret the term “Holy Spirit” in this context as referring to the Archangel Gabriel, who is regarded as the angel responsible for conveying divine revelation (cf. Qurʾān 2:87, 2:253, and 5:110). In this interpretation, Gabriel is understood as the intermediary through whom the Qurʾānic message was communicated to the Prophet.
Al-Rāzī offers an additional perspective concerning the mention of abrogation of certain verses or rulings in the preceding passage. He suggests that the process of abrogation served as a test for believers. According to this interpretation, the replacement or modification of earlier rulings required believers to maintain their trust in the divine origin of revelation and in God’s wisdom. Those who continued to accept the changes with faith demonstrated the firmness of their belief and their commitment to the path of their religion.
References:
Nasr, Hossein (2015). Study Quran.