The shirt off somebody's back - Idioms by The Free Dictionary
the shirt off somebody's back
the shirt off (one's) back
Anything or everything one owns or has to offer. Those contractors will take the shirt off your back if you hire them. I mean, I paid them an exorbitant amount of money, and look at the shoddy work they did! I'm not surprised that Tammy loaned you money—she would give you the shirt off her back if you needed it.
the ˌshirt off somebody’s ˈback anything that somebody has, including the things they really need themselves, that somebody else takes from them or they are willing to give: He’s the type of person who would give the shirt off his back if he thought it would help.