Charity begins at home

I am trying to find the meaning/origen of the saying "Charity begins at home" Thanks!

The Oxford English Dictionary explains the phrase this way: "used to express the prior claims of the ties of family, friendship, etc., to a man's consideration (cf. I Tim. v. 8, etc.)." It gives quotations showing the use of this phrase or variants of it from 1382 through 1798.

I looked up the Biblical passage, and it didn't help.