Arachin 28 - Promise to the Temple is Like Deed with People
If bidders offered respectively ten, twenty, thirty, forty, and fifty shekels for a field consecrated to the Temple, and then one who has bid fifty retracted, he is still responsible to add his ten shekels to the forty-shekel bid. If afterwards the one who has bid forty retracted, they pay ten shekels each. However, if they retracted simultaneously, the one who has bid fifty is responsible for his ten, and for half of the other one's ten, so he pays fifteen, while the other one pays five.
One can "dedicate" his property by making it forbidden ("cherem") to himself, and then assign it either to the Temple or to the Kohanim. All donations that we learned about so far were promises, this one is actual giving over, only it works in two steps: it becomes forbidden to him immediately, and it either remains forbidden in the possession of the Temple until redemption, or it becomes permitted to the Kohanim once they take possession of it.
One can dedicate ("cherem") some of his sheep, cattle, of fields, but not all of them. In general, one should have pity on his possessions and not give away everything - as a guideline, no more than one-fifth.
Art: Camille Pissarro - Flock of Sheep in a Field after the Harvest