Abu Dawud

Benefits and Issues:
➊
The meaning is that we do not deny their outward declaration of faith; rather, we entrust their matter to Allah.
If they are sincere, then they will be honored in the sight of Allah, and if the opposite is true, then they will be criminals in the sight of Allah.
But we will deal with them according to what is apparent.
From this, the principle is derived that an Islamic state is bound to judge according to the apparent conditions of the people,
because knowledge of the inner reality is only with Allah.
And He alone will judge accordingly on the Day of Resurrection.
That is why it is said:
(Nahnu nahkumu bizzawahir wallahu yatawalla as-sara’ir) — We can only judge by what is apparent,
while hidden matters are entrusted to Allah.

➋
There is consensus on killing a disbelieving spy.
But a Muslim should not be killed,
even if he is a hypocrite.

➌
In the chapter, the mention is of a dhimmi spy.
Whereas in the hadith, there is no explicit mention of Hazrat Furat being a dhimmi.
However, this same narration is found in "Muntaqa al-Akhyaar" with reference to Musnad Ahmad.
In that, it is explicitly stated that the Prophet (sallallahu alayhi wa sallam) ordered his killing,
wa kana dhimmiyyan — and he was a dhimmi.
With these words, the relevance to the chapter also becomes clear,
and the permissibility of killing a dhimmi spy as well (Awn al-Ma’bood).

➍
Furat bin Hayyan later accepted Islam,
and proved to be a very excellent Muslim.
He migrated and, during the lifetime of the Messenger of Allah (sallallahu alayhi wa sallam), participated in jihad in his company.
Later, he settled in Kufa.