put (someone, something, or oneself) at (one's) disposal
To make someone, something, or oneself ready and available to help or serve one. This is my butler—I have put him at your disposal for your time with us at the manor. My parents said they'd put their apartment in London at our disposal during our vacation.
put someone or something at someone's disposal
to make someone or something available to someone; to offer someone or something to someone. I'd be glad to help you if you need me. I put myself at your disposal. I put my car at my neighbor's disposal.
put at someone's disposal
Allow one to use, as in They put their car at our disposal for our entire stay. This idiom employs disposal in the sense of "the liberty or power to use something," a usage dating from the early-1600s.