The saying, “Charity begins at home”, means that we should help our own family members and relatives financially and in other ways—BEFORE we help outsiders and strangers.
Step-by-step explanation:
I've always interpreted it as meaning “how can we help you, when we can't help ourselves”
Or - “how can we offer what we don't have”
And in reference to food; “how can we feed anybody else, when there is no food on our table”