Redox Reactions

Guys,in the redox reaction of concentrated sulfuric acid with the halide ions,from where exactly does the halide ions come from?Does it come from the metal halides,or from the hydrogen halides???

It can come from a salt, such as NaCl (you described as metal halide)
Not with hcl and H2SO4 -aqua regia

Thank you for your response!
So,the halide ions come from the salts(like NaCl,KCl etc..)
By the way,I also have another question.Where does the hydrogen ions come from in the reduction of sulfuric acid?Does it come from its own ionisation?

‘The concentrated sulphuric acid gives a hydrogen ion to the halide ion to produce a hydrogen halide. Because this is a gas, it immediately escapes from the system. If the hydrogen halide is exposed to moist air, you see it as steamy fumes.

As an example, concentrated sulphuric acid reacts with solid sodium chloride in the cold to produce hydrogen chloride and sodium hydrogensulphate.

NaCl + H2SO4 -> HCl(g) + NaHSO4

All of the halide ions (fluoride, chloride, bromide and iodide) behave similarly.’
https://www.chemguide.co.uk/inorganic/group7/halideions.html#:~:text=The%20concentrated%20sulphuric%20acid%20gives,see%20it%20as%20steamy%20fumes.