1. Section 58 of the Transfer of Property Act defines “mortgage”, “mortgagor”, “mortgagee”, “mortgage-money” and “mortgage-deed”. A mortgage is the transfer of an interest in specific immovable property for the purpose of securing the payment of money advanced or to be advanced by way of loan, an existing or future debt, or the performance of an engagement that may give rise to a pecuniary liability.

2. The transfer is called a mortgagor, the transferee a mortgagee; the principal money and interest of which payment is secured for the time being are
called the mortgage money, and the instrument (if any) by which the transfer is effected is called a mortgage deed.

3. In simple words, a mortgage is a transfer of an interest in immovable property for securing loans. Therefore, in leases where the lease deed
provides for prior permission of the lessor for the assignment of leasehold rights, it shall be obligatory for the lessee to obtain prior permission from the
lessor before mortgaging the premises. Failure to do so shall amount to a breach of lease terms on which the property can be re-entered.