first, foist

First or first means before in time, order, importance, or rank--
You go first; we're all too nervous.
The first thing we need to arrange is internet service.

Foist or foist means to impose upon by force or deception; to include by fraud--
He tried to foist an imitation on them, but they noticed the difference in quality.
Don't try to foist any of your jailhouse lawyer philosophy on these people; they'll think we're felons.


Now that you know that, you can say--
"Our customers come first. We can't foist this inferior stuff on them; we'll use it ourselves."

Note--Foist may also be used, when writing an attempt at a Bronx or Brooklyn accent, to mean "first"--
"Dey have a man on foist and thoid. Throw da ball home."