In fact man is a witness against himself,

In fact, man himself is keeping an eye on his state of affairs!

nay, man shall be a clear proof against himself,

nay, but man shall against himself be an eye-witness,

Aye! man against himself shall be an enlightenment.

Nay! Man will be a witness against himself [as his body parts (skin, hands, legs, etc.) will speak about his deeds].

And man will be evidence against himself.

And man will be evidence against himself.

And man will be evidence against himself.

And man will be evidence against himself.

In fact, people will testify against their own souls,

But lo, man is well aware of himself,

Nay! Man will be well informed about himself,

Oh, but man is a telling witness against himself,

Indeed, man is a witness to himself,

He shall be a clear proof against himself,

Rather, man, against himself, will be a witness,

In fact, people are well-aware of their own soul

Nay! man is evidence against himself,

Bali alinsanu AAala nafsihi baseeratun

bali l-insānu ʿalā nafsihi baṣīratun

Indeed, man shall be a witness against himself,

Nay, man will be evidence against himself,