lay (someone or something) against (something)
To lean or rest someone or something against something else. We had to lay the injured soldier against the side of a tree while we scouted the surrounding area. Just lay that painting against the wall for the time being.
lay something against something
to lean or place something against something. They laid the Christmas tree against the house where they could get to it easily when the time came. Lay this hot cloth against the sore and hold it there.