I muttered, knocking my knuckles through the glass, and stretching an arm out to seize the importunate branch; instead of which, my
fingers closed on the fingers of a little, ice-cold hand!
Which figurative language is used in the sentence given?

Alliteration.

Explanation:

Alliteration is a literary device that refers to the use of the same consonant word in consecutive words in a sentence. In other words, we can say that alliteration is when the same consonant sound in close proximity in a sentence.

In the given sentence from "Wuthering Heights" by Emily Bronte, the author/ speaker uses the figurative language of alliteration. Alliteration is seen/used in the words "knocking my knuckles" and "fingers closed on the fingers . . ."

Thus, the correct answer is alliteration.