Among the important references in the science of rhyme and what was stated in it: "Hebron said:" The rhyme is the letter that the poet requires at the end of each house in order to finish his hair. "Abu Al -Hassan Muhammad bin Ahmed bin Kisan Al -Nahwi said: The rhyme is everything that must be returned at the end of the house. Ibn Jenni (d. 392 AH) said: "He painted in it with the words of Hebron, and did not do it without a defect that would follow it, which is that it is necessary to cut the rhyme and its difference and intercept things between it that is not from them. (