The Prophet (ﷺ) Said: The children of a man come from what he earns, rather they are his pleasantest earning; so enjoy from their property.

Abu Dawud said: Hammad b. Abi Sulaiman added in his version: "When you need." But this (addition) is munkar (not authoritative).
Sunan Abi Dawud Book 24, Hadith 114