Indeed, all praise and blessing are Yours,” is preferable to reading anna.

Three explanations have been offered for al-Kisā’ī’s reading.

The first is that the testimony applies to both statements. It applies to “Indeed, the religion with Allah is Islam,” which is what is testified to, while annahu in “that there is no deity but Him” is read with an initial a because a preposition has been omitted: the sense is “to the fact that there is no deity but Him.” This is al-Farrā’s explanation. It is very weak, for the meaning points otherwise: what is testified to is precisely the statement “that there is no deity but Him.” Thus, the object of the testimony is inna and the clause it governs. This is the focus of attention and the point being established.

Nevertheless, despite its weakness, this interpretation has a possible basis: the meaning would be that Allah testifies, by affirming His oneness, that the religion with Allah is Islam. Islam is the affirmation of His oneness, glorified is He. The testimony would thus encompass both the affirmation of His oneness and the confirmation that His religion is Islam and no other.

The second explanation is that the testimony applies to both statements together, each being testified to, with wāw (“and”) understood though omitted. The implied wording is: “and that the religion with Him is Islam.” The conjunction is dispensed with because the sentence itself contains a reference to the preceding statement to which it is joined. Similarly, it is dispensed with in His words:

18:22 “They will say, ‘Three, their dog the fourth,’ and they will say, ‘Five, their dog the sixth.’”

Both including and omitting wāw are appropriate: it is omitted here, but included in His words:

18:22 “And they will say, ‘Seven, and their dog the eighth.’”

The third explanation—the position of the Basran grammarians—is to treat the second an-clause as an appositional substitute for the first. The underlying construction is: “Allah testifies that the religion with Allah is Islam.” His words “that there is no deity but Him” prepare the way for and introduce the second clause. This would be a form of apposition in which the second expression refers to the very same thing as the first. For the religion that is Islam itself in Allah’s sight consists in testifying that there is no deity but Allah and fulfilling the obligations of that testimony. On this interpretation, you may also regard it as a case of apposition