waiver of interest on delayed payment

GST on interest received from debtors of a business will be applicable. In other words, interest charged and collected by a supplier on a supply has to be included in the transaction value and GST is liable to be paid on the same.
If a supplier decides to waive off the interest which is due from a customer on delayed payment, GST will not be applicable on the interest.

as per which section, gst n/a on waiver?

Sir, can you plz also quote the section