A covenant in any mortgage in the words, “That will pay the indebtedness as hereinbefore provided” shall be construed to have the same force and effect as the following words:

“And the said for himself, his heirs, executors, administrators or successors covenants and agrees to pay unto the said party of the second part, his heirs, executors, administrators, successors or assigns, the said sum of money and interest as mentioned above and expressed in the conditions of the said bond.”