Musnad Ahmad 555:1

Abu al-Nadr narrated to us, Hariz narrated to us, from Abd al-Rahman ibn Maysarah, from Jubayr ibn Nufayr, from Busr ibn Jahhash al-Qurashi, that the Prophet, peace and blessings of Allah be upon him, spat one day into his palm, then placed his finger upon it, then said: "Allah says: 'O son of Adam, how can you weaken Me when I created you from the likes of this? Until, when I fashioned you and proportioned you, you walked between two garments, and the earth resounded with your footsteps. You gathered and withheld, until when [your soul] reached the collarbones, you said: "I will give charity," and when is the time for charity?'"