they will have achieved what they sought: violating the honour of the person against whom testimony was given.

As for those who maintain that it is not a condition for them to be in a single sitting, they argue that the verse is general:

“Why did they not produce four witnesses to it?” [Surah al-Nur 24:13]

These four witnesses came before the judge and established their testimony. So where, in the Book of Allah or in the sunnah of the Messenger of Allah, is it stipulated that they must be in a single sitting?

Your argument that collusion is to be feared is itself undermined by your view that their testimony is accepted whether they come before the judge all together or separately. For perhaps those who testified in the first hour may collude with those who testify in the third or fourth hour, for example. Had you instead said, as Abu Hanifah and a group of scholars said, that they must come before the judge and give their testimony together in one sitting—meaning that if they come separately, they are slanderers—then we would have three views:

The first: that a single sitting is required and that they must all be present together.

The second: that a single sitting is not required.

The third: that a single sitting is required, but not their simultaneous presence. This is the authoritative position in our school. However, the other two views are more consistent with the underlying principle: either we require them all to come and testify together, or we do not impose such a requirement. The view more closely supported by the textual evidence is that it is not a condition, because the texts are general.

Accordingly, the statement, “in a single sitting,” is not a condition according to the stronger view.

And the statement, “concerning one act of zina,” means that they must testify to one act of zina,