expression
figuratively speaking; metaphorically speaking; so to speak
Used to introduce a figurative or metaphorical explanation, often to make an abstract idea easier to understand.
人生は、例えて言うと、長い旅のようなものだ。
Life, figuratively speaking, is like a long journey.
彼の気持ちは、例えて言うと、迷路に迷い込んだようなものだった。
His feelings were, so to speak, like being lost in a maze.
言わば is more like 'as it were' or 'in a manner of speaking', often used to rephrase or qualify a statement, while 例えて言うと explicitly introduces a comparison or metaphor.
例えば means 'for example' and introduces a concrete instance, whereas 例えて言うと introduces a figurative comparison.
From 例える (to compare, to liken) in the te-form + 言う (to say) + conditional と, literally 'if one says it by comparing'.