Riyad as-Salihin

'Abdullah bin Yazid Al-Khatmi (May Allah be pleased with him) reported: When Messenger of Allah (ﷺ) intended to bid farewell to his army he would say: "Astau-di'ullaha dinakaum, wa amanatakum, wa khawatima 'amalikum (I entrust Allah with your Deen, your trust and your last deeds)."

[Abu Dawud].