The Prophet ﷺ spat into his palm, then placed his index finger upon it and said, "Allah says, 'How can you defy Me, son of Adam, when I created you from something like this? Yet when your soul reaches here,'" pointing to his throat, "'you say, I will give in charity, but how can it be the time for charity then?'"
حدثنا أبو بكر بن أبي شيبة حدثنا يزيد بن هارون أنبأنا حريز بن عثمان حدثني عبد الرحمن بن ميسرة عن جبير بن نفير
بزق النبي ﷺ في كفه ثم وضع أصبعه السبابة وقال يقول الله عز وجل أنى تعجزني ابن آدم وقد خلقتك من مثل هذه فإذا بلغت نفسك هذه وأشار إلى حلقه قلت أتصدق وأنى أوان الصدقة
[Its chain of transmission is sahih] Ahmad narrated it: 4/210, and others, through several routes from Hurayz with this wording, and Thawr bin Yazid Rahbi corroborated him, as found in Tabarani: 2/32, and Hakim graded it sahih: 2/502, 4/323, as did Dhahabi and Busiri.