Bukhari

Hadith Commentary:
Khabab (radi Allahu anhu) worked for ‘As ibn Wa’il, even though he was a disbeliever and a resident of the land of war (dar al-harb).
From this, the heading of the chapter is established.
‘As ibn Wa’il said this to Khabab (radi Allahu anhu) in a mocking manner.
Allah the Exalted revealed the aforementioned verse in condemnation of him: “O Prophet! Have you seen the disbeliever who denies Our signs and says, ‘I will surely be given wealth and children after I die?’” It is as if he has obtained some covenant from Allah.

Hadith Commentary:
(1)
Imam Bukhari rahimahullah has established from this hadith that Khabbab radi Allahu anhu was a Muslim and ‘As ibn Wa’il was a polytheist (mushrik).
Khabbab radi Allahu anhu performed work for ‘As ibn Wa’il in Makkah al-Mukarramah, which at that time was a land of war (dar al-harb), for a wage.
The Messenger of Allah sallallahu alayhi wa sallam became aware of this, maintained it, and did not object to it in any way.
(2)
Imam Bukhari did not make a definitive ruling regarding this matter, because there was a possibility that this action was done out of necessity, or that the command to fight the polytheists had not yet been revealed, and this incident occurred before that.
Some scholars have issued a fatwa permitting this with two conditions:
٭ The work must be lawful and permissible for Muslims, i.e., one should not take wages for slaughtering swine or distilling alcohol.
٭ There should be no fear of any harm to Muslims from this work, i.e., it would not be permissible to take wages for manufacturing weapons, etc., for the disbelievers.
According to our inclination, in case of necessity and with the aforementioned conditions, there is no harm in working for disbelievers and polytheists, but it cannot be declared absolutely permissible.
And Allah knows best.