Grading: Its chain is "hasan", but what is preserved in the narration of Amr bin Shu'ayb is that whoever says it "200 times" a day, as in some narrations from him, or in others 100 times in the morning and 100 times in the evening.

Technical note: Abu Qilabah is Abd al-Malik bin Muhammad al-Raqashi, Abu Zafar is Abd al-Salam bin Mutahhir al-Azdi, and Thabit is Ibn Aslam al-Bunani.

Reference / Source: Al-Nasa'i (10337) narrated it by way of Ibrahim bin Ya'qub, from al-Hajjaj bin Minhal alone, with this chain, and it says: "Whoever says in a day 200 times".

Reference / Source: Imam Ahmad (11/6740) from al-Hasan bin Musa al-Ashyab and (7005) from Affan bin Muslim, both from Hammad bin Salamah, narrated it, and they too said "200 times".

Reference / Source: Al-Nasa'i (10336) narrated it by way of Abd al-A'la bin Abd al-A'la, from Dawud bin Abi Hind alone, also with the words "200 times".

Reference / Source: Al-Nasa'i narrated it by way of Shu'bah from al-Hakam bin Utaybah (10335) and by way of al-Awza'i (10588), both from Amr bin Shu'ayb; al-Hakam said in his narration "100 times in the morning and 100 times in the evening", and al-Awza'i said "100 times before sunrise and before sunset".

Corroborating chains and supporting reports: It has a supporting report in the hadith of Abu Hurayrah (may Allah be pleased with him) in al-Bukhari (3293) and Muslim (2691), whose wording is: "Whoever says: There is no god but Allah alone, with no partner; His is the dominion and His is the praise, and He has power over all things, 100 times in a day, it will be equal for him to freeing ten slaves, 100 good deeds will be recorded for him, 100 bad deeds will be erased from him, it will be a protection for him from Satan that day until evening, and no one will bring anything better than what he brought except one who did more than that."

Important point: Ibn al-Mulaqqin, in "Mukhtasar Talkhis al-Dhahabi" (126), objected to this statement of the author (Imam al-Hakim), saying: This is strange of al-Hakim, for he himself narrated from him at the beginning of the chapter on prayer (726) the hadith "Command children to pray at seven" (the hadith), and it is strange of al-Dhahabi how he let it pass.
Note / Clarification: We say: rather, the strange thing is Ibn al-Mulaqqin, for he did not notice that Imam al-Hakim did not cite that hadith as proof but mentioned it only among the supporting reports; indeed, he himself pointed to a defect in it, namely that Shu'ayb (the father of Amr) did not hear from his grandfather Abd Allah, and we have discussed this defect there.