Hi Candidate!

You can begin your speech by welcoming the new recruit with the greetings like :

I welcome you as a new addition of our company ( company name, if you feel) or you can say; " on the behalf of the management, I welcome you to our office."

Then you can continue by making the person comfortable with the words: Hope you are doing good or I believe  you will find your new position rewarding. We all look forward to work with you.

Next, you can tell him the brief of his work or you can tell him that he be given instructions/brefing of his work further by colleagues or seniors. Amd for any doubt or clarification he might reach out to his seniors or to you.

End the speech by asking to fill out the necessary paper work with the HR manager."Welcome aboard" or "all the best"

Thankyou!