“I know the laws of allegory, though less by myself than from the works of others. There are those truly, who do not admit the common sense of the Scriptures, for whom water is not water, but some other nature, who see in a plant, in a fish, what their fancy wishes, who change the nature of reptiles and of wild beasts to suit their allegories, like the interpreters of dreams who explain visions in sleep to make them serve their own ends. For me grass is grass; plant, fish, wild beast, domestic animal, I take all in the literal sense. ‘For I am not ashamed of the Gospel’ [Romans 1:16].
‘And there was evening and there was morning: one day.’ And the evening and the morning were one day. Why does Scripture say ‘one day the first day’? Before speaking to us of the second, the third, and the fourth days, would it not have been more natural to call that one the first which began the series? If it therefore says ‘one day,’ it is from a wish to determine the measure of day and night, and to combine the time that they contain. Now twenty-four hours fill up the space of one day — we mean of a day and of a night; and if, at the time of the solstices, they have not both an equal length, the time marked by Scripture does not the less circumscribe their duration. It is as though it said: twenty-four hours measure the space of a day, or that, in reality a day is the time that the heavens starting from one point take to return there. Thus, every time that, in the revolution of the sun, evening and morning occupy the world, their periodical succession never exceeds the space of one day.”
— St. Basil the Great, Hexaemeron, Homily 2