Musannaf Ibn Abi Shayba 13:1167

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Isra’il narrated to us, from Abu Husayn, from Khalid ibn Sa’d, from Abu Mas’ud al-Ansari: That when [sweets or coins] were scattered upon the children, he would prevent his own children [from taking them], and he would buy for them [instead].