"conquer by flood and by field"

Question

While reading an English poem from Robert M. M'Cheyne (1813–1843), Jehovah Tsidkenu (= Jehovah our Righteousness) there is one stanza that reads

Jehovah Tsidkenu! my treasure and boast,
Jehovah Tsidkenu! I ne’er can be lost;
In thee I shall conquer by flood and by field,
My cable, my anchor, my breast-plate and shield!

I'm particularly interested to know the meaning of "conquer by flood and by field". I know what each word means on its own, yet this sounds like there's more to it than meets the eye.

Answer 1

There were several prior uses of the phrase "by flood and by field" and "by flood and field". It means by water and by land.

For example, The Enigmatical entertainer and mathematical associate for the year 1829, No. II at page 56 says:

While he will his “ voyages and travels ” recount , “ By flood and by field " what he's had to surmount

The OED has 2 poetic definitions of the word "flood":

A body of flowing water; a river, stream, usually, a large river

and

In wider sense: Water as opposed to land, often contrasted with field and fire