The writer didn’t tell us anything about himself, but we can deduce some points anyway. The shift of *b > m in Kimsi “Id al-Adha” < *kibsi (< Arabic kabš “ram”) is recorded by Heath as a dialect feature specific to the town of Niafounké, 150 km upstream from Timbuktu at the opposite end of the Koyra Chiini-speaking region; the Timbuktu form is cipsi / ciwsi. The same irregular shift is found in Dedem “Muharram” < *dedeb, for which no Niafounké form is recorded by Heath, contrasting with Timbuktu dedew, Goundam dedeb; Hacquard and Dupuis (1897) already record dédo, so the Timbuktu form is at least a century old. (Why “rest of the holidays”? Because feer-mee, which he’s already given, also means “Id al-Fitr”.)
Now, whereas the rural population surrounding Timbuktu is mainly Tuareg, that around Niafounké is mainly Fulani. When the author lists ethnic groups, he starts with the Fulani, and he consistently uses a third person plural “they” to refer to Songhay speakers. This suggests that he himself is probably a Fulani from around Niafounké, rather than a native citizen of Timbuktu. Fulani speakers have an unusually strong tradition of writing their own language in Arabic script, as illustrated by the other two manuscripts mentioned, so this might make sense.
But what was he doing writing this anyway? Obviously he didn’t need it... but others did. In fact, we can safely say that this poem was actually used by at least one student - the version seen is clearly not the original, since it contains a copying error. Surgu "Tuareg" is written شرع, with the wrong dots, as if the copyist mistook it for the Arabic word "he began". This is explained by the circumstances in which it was written.
At the advanced level, the schools of Timbuktu attracted students from as far away as Algeria or southern Mali. For it to be worthwhile to go there at all, they would have to have already spent years studying Classical Arabic – and much of their study would have taken the form of memorising didactic poems, such as the Ājurrūmiyyah or Alfiyyat Ibn Mālik for grammar. But if their studies took place outside the Songhay region, they would arrive not knowing the dominant language of the town. This poem is tailored for such students. I’ve heard reports of similar poems at Kabyle zaouias intended to help Arabic-speaking students attracted by the zaouia’s reputation to learn Kabyle, though I can’t track the reference down at the moment; so, in a sense, this can be considered part of a much wider genre. At the least, it represents an obvious solution to a problem recurring in higher-level schools all over North and West Africa.
The organisation of the poem reflects that environment. Schools were, first and foremost, Islamic schools; thus the author opens not with the commonest vocabulary but with the basic concepts of religion, starting in the order of the Five Pillars of Islam – shahada, prayer, and fasting (but not zakat or pilgrimage, which would both be financially out of the reach of many students.) He continues with that theme, going through the motions of the prayer ritual in the appropriate order (ablution, saying “Allāhu akbar”, reading from the Qur’an, and finally greeting the angels and asking favours of God), and then starting with the meals associated with fasting before moving on to the meals of non-fasting times. Having covered the basic Islamic rituals that structured their day and their year, he only then moves on to other topics – specifically, ethnicity. For a new student from outside the area, travelling so far perhaps for the first time, the variety of ethnic groups represented in Timbuktu, a crossroads between the Sahel and the Sahara, must have been striking, and being foreign would have heightened his awareness of his own ethnic identity.
Note that the author nowhere uses the term “Songhay”. This is not at all surprising. In Timbuktu, Songhay (Soŋoy) traditionally refers primarily to the noble families of the Songhay Empire, in particular the Maïga family. These families had a reputation for sorcery which did not match well with the ethos of the schools, and were in any case only a small minority of the population speaking what is now called Songhay. The term he uses, Gaa-bibi, has a broader sense, being used for the ordinary Songhay-speaking farmers of the area; it literally means “black body” and thus corresponds almost exactly to the Arabic term “Sūdān” that he also uses. “Koyra Chiini” means “town language”, and as such does not correspond in particular to any one ethnic group.
Other points of linguistic interest: Laarab “Arab” is a conservative form compared to what Heath records – laarow (Timbuktu) / laaram (Niafunké, Goundam) – but this is perhaps natural, given than the author is a student of Arabic. Sete, glossed here as "guest", is rendered by Heath as "caravan"; visiting caravan members would stay as guests of particular families. Cirkose and cirkaarey are treated as synonyms for “lunch”; this is confirmed by the earliest dictionary of Koyra Chiini, Hacquard and Dupuis (1897), but at present they have distinct meanings, cirkaarey being “breakfast”. The forms jiŋgar “pray” < *gingar and jur “run” < *zuru illustrate the characteristic innovation of Koyra Chiini, *z and *g / _[+front] merging to j.