The obligation to disclose, fully and correctly, the income that was earned by the assessee during the assessment period, was on the assessee himself, and if the department had issued notices to the assessee seeking for documents to substantiate his claim for exemption, then that cannot be treated as a new proposal by the department to fasten a liability on the petitioner. Accordingly, there was no obligation on the department to afford yet another hearing to the petitioner before passing the assessment order. In the instant case, the various queries raised by the department after perusing the reply given by the assessee to the notice issued under Section 143(2) of the Income Tax Act would clearly reveal that the department was only seeking for the documents that would substantiate the claim of the petitioner assessee for exemption in respect of a substantial portion of the income that was declared by him in the return. Ultimately, by Ext. P17 assessment order, all that the department did, was to deny the claim for exemption of the petitioner assessee, and while doing so, the department was not obliged to grant any hearing to the petitioner over and above the opportunities that had already been extended to the petitioner to respond to the specific queries raised by the department. In my view, there cannot be a mechanical application of the principles of natural justice in every case and the necessity of affording a hearing to an assessee, in order to comply with the rules of natural justice, must be examined on the facts of each case.