I heard Abu Qasim ﷺ say, "By the One in whose hand my soul rests, not one of you will enter Paradise by his deeds alone."They asked, "Not even you, Messenger of Allah?"He replied, "Not even me, unless Allah envelops me in His mercy and grace," and he placed his hand on his head.
حدثنا بهز حدثنا حماد عن محمد يعني ابن زياد
سمعت أبا القاسم ﷺ يقول والذي نفسي بيده إن منكم من أحد يدخله عمله الجنة قالوا ولا أنت يا رسول الله قال ولا أنا إلا أن يتغمدني الله منه برحمة وفضل ووضع يده على رأسه
Its isnad is sahih, it has been mentioned frequently before, see 7202 and 8233. It is found in Bukhari 8/122-123, in "the Book of Softening of Hearts," chapter "Moderation and Perseverance in Deeds," and in Muslim 4/2169, no. 2816, in "the Book of the Descriptions of the Hypocrites," chapter "No One Will Enter Paradise by His Deeds Alone," and in Ibn Majah 2/1405, no. 4201, in "the Book of Asceticism," chapter "Steadfastness in Deeds."