The Messenger of Allah ﷺ said, "The best charity is that given out of surplus wealth. Begin with those whom you support. The upper hand is better than the lower hand."I asked Ayub, "What does 'out of surplus wealth' mean?"He replied, "From what exceeds your needs."
حدثنا عبد الرزاق حدثنا معمر عن أيوب عن ابن سيرين
قال رسول الله ﷺ خير الصدقة ما كان عن ظهر غنى وابدأ بمن تعول واليد العليا خير من اليد السفلى قلت لأيوب ما عن ظهر غنى قال عن فضل غناك
Its isnad is sahih. It is a repetition of 7155, and an extended version of 7342. We have already referred to this at both of those places.