Looks like some kind of pledge to indemnify the heirs/beneficiaries (if one of the partners dies) from any debts, liabilities or other claims arising out of or in connection with the stuff they will get.
see: "
What should be included within a cohabitation agreement?Financial issues are a major part of a cohabitation agreement.
The agreement must cover what rights each partner has in relation to the property you live in, who owns what assets and
who is responsible for any debts. The agreement can also look at how you will share expenses while you live together. If you have children either jointly or with a previous partner this should also be addressed within the agreement." (
http://www.bannerjones.co.uk/frequently-asked-questions?page... )
We need more context. E.g., who exactly are "de erfgenamen"?