int~ _another, and therefore the Explanation in cl. (I )(a) cannot lcg1u_mately be extended to cl. (2) either as an exception or as a proviso thereto or read as curtailing or limiting the ambit of cl. (2). This Court further held that until the Parliament by law, made in exercise of the powers vested in it by cl. (2) of Art. 286, provides otherwise no State may impose or authorise the impositio'.I of any tax on sales or purchases of goods when such sales or purchases take place in the course of inter-State trade or commerce, and therefore the State Legislature could not charge interState sales or purchases until the Parliament had otherwise provided. The judgment of the Court in the Bentral Immunity Company's case(1 ), was delivered on September 6, 1955. The President issued the Sales Tax Laws Validation Ordinance, 1956, on January 30, 1956, the provisions of which were later embodied in the Sales Tax Laws Validation Act, 1956. Ry this Act notwithstanding any judgment, decree or order of any Court, no law of a State imposing, or authorising the imposition of, a tax on the sale or purchase of any goods where such sale or purchase took place in the course of inter-State trade or commerce during the period between the !st day of April, 1951 and the 6th day of September, 1955, shall be deemed to be invalid merely by reason of the fact that such sale or purchase took place in the course of inter-State trade or commerce; and all such taxes levied or collected or purported to have been levied or collected during the aforesaid period shall be deemed always to have been validly levied or collected in accordance with law. The Parliament thus removed the ban contained in Art. 286(2) of the Constitution retrospectively but limited only to the period between April l, 1951 and September 6, 1955. All transactions of sale, even though they were inter-State could for that period be lawfully charged to tax. But Art. 286(2) remained operative after September 6, 1955 till the Constitution was amended by the Constitution (Sixth Amendment) Ac!, i.e., September 11, 1936. By the amendment, the explanation to cl. (I) of Art. 286 was deleted and for els. (2) and (3) the following clause$ were substituted :