Sometimes repetition of a word has an intensifying effect.  We have examples of this in English:

1. (Me to my kids sometimes): If you don’t start acting right, we’re going to have a big, big problem.

2. The pope has resigned. It’s a sad, sad day.

I recently came across my favorite example of this so far in Hebrew in Ecclesiastes 7:24:

There is a repetition of ‘amoq, (for my non-Hebrew reading audience … Ha! As if anyone reads this blog). It is often rendered as “deep,” which here would be a metaphor for being difficult to understand or mysterious.

The translations vary:

That which is, is far off, and deep, very deep; who can find it out? (NRSV)

Whatever has happened is beyond human understanding;

it is far deeper than anyone can fathom. (NET)

That which has been is far off, and deep, very deep; who can find it out? (ESV)

What has been is remote and exceedingly mysterious. Who can discover it? (NASB)

The UBS Handbook on Ecclesiastes offers the following:

Complementing the adjective far off is the adjective ̀amoq deep. The repetition of the adjective ̀amoq ̀amoq has a superlative sense, “the deepest deep.” It also has a stylistic, or literary, function, providing assonance or similar sounding words, as rachoq (“far”) and ̀amoq sound alike. Thus deep, very deep reinforces the fact that the things of the world cannot be penetrated by the limited human mind. See this same idea in Pro 18:4; 20:5; Psa 64:6. “The deepest deep” may have to be expressed in another way. In English, for example, we can modify “deep” by adverbs: “so deep,” “so very deep,” or retain the rsv model. Again, idiomatic expressions or ideophones may be of use here: “beyond my grasp,” “beyond me,” etc. cev combines the two adjectives: “It’s far too deep.”

For myself, to preserve a bit of the otherness of the text, I like to read it something like (completely ignoring the difficulty of translating the earlier part of the verse):

That which is, is far off, and deep, deep; who can find it out? (NRSV)