The Messenger of Allah ﷺ said, "Shall I inform you of the best of your deeds, the purest of them in the sight of your Sovereign, the highest of them in your ranks, better for you than spending gold and silver, and better for you than meeting your enemy so that you strike their necks and they strike yours?"They asked, "What is that, Messenger of Allah?"He replied, "The remembrance of Allah ."
حدثنا يحيى بن سعيد عن عبد الله بن سعيد حدثني مولى ابن عياش عن أبي بحرية و حدثنا أبي حدثنا مكي حدثنا عبد الله بن سعيد عن زياد بن أبي زياد عن أبي بحرية
قال رسول الله ﷺ ألا أنبئكم بخير أعمالكم قال مكي وأزكاها عند مليككم وأرفعها في درجاتكم وخير لكم من إعطاء الذهب والورق وخير لكم من أن تلقوا عدوكم فتضربوا أعناقهم ويضربوا أعناقكم قالوا وذلك ما هو يا رسول الله قال ذكر الله عز وجل
Its isnad is sahih. Abdullah bin Saeed is Ibn Abu Hind, and he is trustworthy, having narrations in the Sahih. Likewise, the freed slave of Ibn Ayyash is Ziyad bin Abu Ziyad Maysara Makhzumi. Abu Bahriyya is Abdullah bin Qays, one of the senior Tabiin, a mukhadram among the trustworthy narrators.The hadith was narrated by Tirmidhi, 5/459, no. 3377, who discussed its connectedness but affirmed it decisively, and by Ibn Majah, 2/1245, no. 3790. Hakim graded it sahih, 1/496, and Dhahabi agreed with him. Bayhaqi also narrated it in Shuab, 1/394, no. 519.