Dhikr for which Allah forgives sins in the day and night, hasan or gharib (commentary)?

There are two ahadith regarding the Dhikr: "Allahumma Asbahna Nush-hiduka Wa Nush-hidu Hamalata Arshika..." to say it ***once*** and ***four*** times. I want to know specifically for the hadith mentioned in At-Tirmidhi (3501 ) where the Prophet sallahu alayhi wa sallam said, if you say it **ONCE** that: "Allah will forgive him for whatever he does that day, and if he says it in the evening, Allah will forgive him for whatever sin he commits that night". Darussalam says it's **hasan** while At-Tirmidhi states below it that it is **gharib** (*strange*). Is there any commentary from *Ibn Hajar*, *Albani*, *Al-Haythami*, *Al-Mundhiri*, etc. about this hadith? references: ---------------------------------------------------------------------- muflihun.com/abudawood:5069 / sunnah.com/adab:1201 | "*four times*" muflihun.com/abudawood/43/5060 and the above mentioned (3501) | "*once*" (This is the only info, mainly on the “four“-version I got without any idea on how to exploit it any further for my question)