When the Prophet ﷺ wanted to say farewell to an army, he would say: I entrust to Allah your religion, what you are responsible for, and your final deeds. (Using translation from Abū Dāʾūd 2601)
كَانَ رَسُولُ اللَّهِ ﷺ إِذَا وَدَّعَ جَيْشًا قَالَ «أَسْتَوْدِعُ اللَّهَ دِينَكُمْ وَأَمَانَتَكُمْ وَخَوَاتِيمَ أَعْمَالِكُمْ»