Judgement DESAI, C. J. :- The following question has been referred to a Full Bench by a Division Bench particularly for reconsideration of the decision in Dr. A.C. Dass v. T.R.O. and D.S.O. Lucknow, 1962 All LJ 553 :- "When a tenant-in-chief vacates an accommodation by subletting it to another person can the District Magistrate pass an order under S. 7(2) of the Act to him to sublet it to another person or to his landlord, e.g. the owner of the accommodation, to let it to another person. In other words, who is the landlord of the accommodation that falls vacant-the tenant-in-chief or the owner-who can be ordered to let ?" 2. Since an abstract question is referred to us we are not concerned with the facts and I do not consider it necessary to reproduce them. The question is an abstract question of law, the answer to which does not depend upon the facts at all. 3. "Accommodation" is defined in Section 2(a) of the Temporary Control of Rent and Eviction Act to mean residential or non-residential accommodation in any building or part of a building. Really this is not a definition but only an explanation because in defining a word one cannot use that word itself. Accommodation is not a concept like a right but is a tangible property, meaning a building or a part of a building used for residential or non-residential purpose. Whether in respect of a building the whole of it is an accommodation or part of it is an accommodation or whether it consists of more than one accommodation depends upon circumstances such as tenancy contract. See 1962 All LJ 553 (supra) to which I was party. In. N.C. Agarwal v. Krishan Lal Mehra, 1960 All LJ 755 : ( AIR 1961 All 104 FB), Dayal, J. said at p. 757 (of All LJ) : (at p. 106 of AIR) that "the definitions of landlord' and 'tenant' fix the accommodation to be the accommodation for which rent is payable by the tenant to the landlord" and that "the power of determining the unit of tenancy vests in the landlord", it being "his right to let accommodation to a tenant." In these observations landlord means the owner and tenant, his tenant and do not include a tenant-in-chief as against his subtenant. If the whole building is let the whole of it is an accommodation. If the whole building is let the whole of it is an accommodation. If it is let in two parts each part is an accommodation. Though a building in occupation of its owner is an accommodation the Act does not apply to it so long as it remains in his occupation, provided that it had not applied any time in the past also. In respect of a building which was always in occupation of the owner and never let it becomes governed by the Act when he ceases to occupy it or a part of it. If he ceases to occupy the whole Section 7 applies to the whole and the whole becomes one accommodation. If he ceases to occupy a portion only that portion becomes an accommodation governed by Section 7 and the remaining portion, though constituting another accommodation, is not governed by it. When an owner lets a building or a part of it to a tenant there comes into existence one and only one accommodation governed by the Act. When the tenant sublets the whole of it or a portion of it another accommodation does not come into existence on the subletting, not even when it is of a portion. Consequently accommodation in the case of a building let to a tenant-in-chief who has sublet, whether the whole of it or a portion of it means the whole building; in other words, the subletting does not bring into existence another accommodation, accommodation being a tangible property. On reconsideration, I think that a statement to the contrary made by me in Dr. A.C. Dass, 1962 All LJ 553, at p. 555 is not correct. A building, which has become an accommodation governed by the Act, remains one accommodation and cannot become two accommodations merely on its being sublet in whole. If another accommodation does not come into existence when the whole is sublet another should not come into existence also when a portion is sublet. A portion of an accommodation remains an accommodation. 4. "Landlord" is defined in Cl. © of S. 2 to mean a person to whom rent is payable by tenant in respect of an accommodation and "tenant" is defined in Cl. (g) to mean a person by whom rent is, or but for a contract would be payable. A portion of an accommodation remains an accommodation. 4. "Landlord" is defined in Cl. © of S. 2 to mean a person to whom rent is payable by tenant in respect of an accommodation and "tenant" is defined in Cl. (g) to mean a person by whom rent is, or but for a contract would be payable. When a person is liable to pay rent (or is excused from the liability by a contract) he is a tenant and the other person, a landlord. When an owner lets an accommodation to another person he becomes the landlord and the other person, a tenant and when the tenant sublets it, the tenant becomes a landlord and the sub-tenant, a tenant. Thus a tenant-in-chief is the landlord of his sub-te