What is this called when an author or poet refers to something from a piece of literature or some other form of media in his or her writing?

metaphor

cliche

illusion

allusion

yes

explanation:

6  then the  lord  said to cain, “why are you angry?   why is your face downcast?   7  if you do what is right, will you not be accepted? but if you do not do what is right, sin is crouching at your door;   it desires to have you, but you must rule over it.”

8  now cain said to his brother abel, “let’s go out to the field.”  while they were in the field, cain attacked his brother abel and killed him.

consonant blends (also called consonant clusters) are groups of two or three consonants in words that makes a distinct consonant sound, such as "bl" or "spl." consonant digraphs include bl, br, ch, ck, cl, cr, dr, fl, fr, gh, gl, gr, ng, ph, pl, pr, qu, sc, sh, sk, sl, sm, sn, sp, st, sw, th, tr, tw, wh, wr.