A Simple Argument
Experience of Hazrat Mirza Tahir Ahmad (ra) explaining “Khatam”.
Experience
In his student years, Hazrat Mirza Tahir Ahmad (ra) used to study Arabic at school, on a test a certain Caliph’s name was presented in English, the question was to write this Caliph’s name as “the last Caliph” in Arabic. Hazrat Mirza Tahir Ahmad (ra) wrote on purpose, “Khatam al Khulufa” (The Seal of the Khulufa), as the translation of “the last Caliph” into Arabic. When the teacher saw this answer, he put a red line on it, the teacher said this is the wrong answer! Hazrat Mirza Tahir Ahmad (ra) said, “No! This is the right answer.” The teacher argued, “I know better Arabic than you, this is not the translation of the last Caliph into Arabic”. Hazrat Mirza Tahir Ahmad (ra) responded, “Allah knows better Arabic than everyone, yet He said Khatam an Nabiyeen about the Prophet SAW in the Holy Quran to denote Last Prophet according to you, so why doesn’t Khatam al Khulufa mean the Last Caliph!” Thereupon the teacher was left with no answer, and he understood that the meaning of Khatam an Nabiyeen is not “the Last Prophet”.
Point/Challenge
This is common Arabic knowledge, the Caliph Ali (ra) cannot be called “Khatam al Khulufa” even though he is the last Rashidun Caliph, nor can Abdülmecid II, the last Ottomon Caliph be called “Khatam al Khulufa” even though he is the Last Caliph.
This should help the readers understand, that old and modern Arabs, all use “Khatam” to denote “no one like him” rather than last in the order!
It is entirely inappropriate to refer to any person who is the last in line of something to be called “Khatam” of it. The “Khatam al Khulufa” is the “Greatest of the Khulufa”, not last. Ask any Arab linguist or professor, in modern or ancient times.