What is the interpretation of the Almighty's saying (Indeed, disbelievers are those who say that Allah is the third of three) in Surat Al-Ma'idah?

The Christians committed disbelief by their saying that Allah is one of three (a trinity). There is disagreement regarding the intended meaning of this statement. It has been said that they are disbelievers who believe in the three hypostases: the Father, the Son, and the Word. It has also been said that it (the Quranic verse) was revealed concerning their making Christ and his mother two deities alongside Allah, thus Allah becomes one of three (a trinity) from this perspective. This latter opinion is the more evident one.