Not only is this statement false, it is not original and was taken out of context from its source.
Its source was the work of John Locke who penned, “All men are born equally free and independent and have certain inherent natural rights of which they cannot, by any compact, deprive or divest their posterity; among which are the enjoyment of life and liberty, with the means of acquiring and possessing property, and pursuing and obtaining happiness and safety.”
This phrase was adopted by George Mason and incorporated in the Virginia Declaration of Rights as, “That all men are by nature equally free and independent and have certain inherent rights, of which, when they enter into a state of society, they cannot, by any compact, deprive or divest their posterity; namely, the enjoyment of life and liberty, with the means of acquiring and possessing property, and pursuing and obtaining happiness and safety.”
When Thomas Jefferson, an acquaintance and friend of George Mason, adopted it in the Declaration of Independence he shortened it to the phrase, “all men are created equal”. Nothing could be further from the truth and attempts by government to give it credibility and to hide and disguise the fact that all men are not equal have amplified the significance of those differences.
When the Constitution was written, George Mason was a delegate to the Convention and participated in its formulation. Two provisions were incorporated, perhaps to curry his and others of like mind into agreeing to its terms. They were a prohibition against bills of attainder and ex post facto laws.
A bill of attainder is a law singling out an individual or organization for special treatment. In England, it was an edict of the King being able to single out one or a group of his subjects and that was prohibited to him when he signed the Magna Carta. In simple terms, if a law was necessary and to be made it had to apply to everyone equally. An ex post facto law is a law that retrospectively changes the legal consequences of acts committed prior to the enactment of that law. It can be either making an act as an offence with retrospective effect; or increasing the prescribed punishment for an offence committed in the past.
Examples of bills of attainder are every single one of the federal and state tax codes that single out classes of individuals for different tax treatment. Examples of ex post facto laws are the making of things once treated as neither legal or illegal and altering their status. Prohibited or regulated products, either naturally occurring or manufactured are examples. They are things such as hemp, opium, heroin and all medications requiring a prescription as are tobacco, and alcohol.
It was perhaps his fear that putting a prohibition in the Constitution was insufficient to insure the government would not ignore it because there was not a consequence included should it fail to abide by it. He left the Convention being one of those who did not agree and sign the document produced and actively championed its rejection by Virginia. His concerns were not unwarranted.