Two tests govern genuine tashriʿ: each stopping point must yield complete sense, and the alternative endings must preserve the required metre and rhyme.
The line can therefore be heard as a shorter or longer valid poetic unit. Merely finding similar final sounds is not enough if one version is ungrammatical or metrically broken.
Shortened form of the cited verses:
Yā ayyuhā al-maliku alladhī
Mā fī al-kirāmi lahu naẓīr
Law kāna mithluka ākhar
Mā kāna fī al-dunyā faqīr
The shorter form still conveys coherent praise and its own rhyme; the full form adds wording that permits another ending.