Dear Mr Knowles,
I, Mr Jones, the Dean of MES, am writing this letter to make you aware of the acceptance for the leave application which you have submitted last week. You have been one of those members of the staff which have always served for the betterment of the institution and have worked tirelessly for a long period of time. If I am not mistaken this is just the second time you have submitted for a leave application. I completely understand that if it had not been for an urgent issue the necessity for a leave shall never have dawned.
It would be a disgrace to the valuable service which you have provided, if this leave application is not accepted. Hence, for the betterment of all, this leave application is accepted. The institution authorities shall also be providing a holiday leave in the near future, after realising the continuity with which you have served.