Philo Judaeus De Posteritate Caini 95

[95] Now the precept is of this kind, "Of every thing which passeth under the rod, the tenth is sacred to the Lord; thou shalt not exchange good for bad, and if thou dost exchange, both the thing itself and that for which it is exchanged shall be sacred," ¹ and yet how can that which is evil possibly be sacred? The truth is that, as I said, he means here what is laborious, not what is bad; so that what is really intended is something of this kind:—The honourable is a perfect good, but labour is an imperfect advantage. If therefore you acquire what is perfect, you need no longer seek what is deficient; but if with an excessive superfluity you choose still to continue labouring, then know that you will appear to be exchanging one thing for another, but in reality you will be acquiring both, for even if both are of equal value they nevertheless are not completely whole.