Question

the guard said, "Let me do my duty"(narration )​

Answer 1

Answer:

THE GUARD SAID TO LET HIM DO HIS DUTY!!!

Explanation:

HOPE IT HELP$!!!!

Answer 2

Here is your answer:

The requested to be allowed to do his duty.

or

The guard requested that he should be allowed to do his duty.

Explanation

The given direct speech sentence was an imperative sentence.  

When we change an imperative direct speech or vice versa into indirect speech we do the following changes:

1. Reporting verb is changed according to the request, advice, suggestion, or command tone of the sentence.

2. Linking word 'to' is used to join the quoted speech with the reporting verb. In case the sentence is negative 'not to' is used.

3. The other changes of the tense, time adverbials, and pronouns are the same.

Or

Direct speech beginning with the word ‘let’ are very tricky. 'Let' in the sentences has different meanings. So, the reporting verb ‘said to’ is changed according to the idea conveyed by ‘Let’. The reporting verb in indirect speech can be changed into ‘Proposed’, ‘Suggested’, ‘Requested’, ‘Ordered’, ‘Wished’, ‘Told’, etc.