Provisional attachment protects revenue during tax proceedings; Commissioner approval and hearing required with safeguards and threshold requirement. Provisional attachment under section 73C may be initiated only after a show cause notice; a Central Excise Officer must prepare a prescribed proposal and obtain Commissioner approval or the Commissioner may order attachment if proceedings are before him. The Commissioner must afford a fifteen day opportunity to make submissions, restrict alienation of specified property, notify registration authorities for immovable property, and, if satisfied, approve attachment by written order. Attachments must be proportionate to the demand, inventoryed, effected between sunrise and sunset, subject to a time limit with possible extensions, and exclude personal-use property and items exempt from civil execution.