Question

Explain the statement Repulsion is a sure test of a permanent magnet

Answer 1

Repulsion is evident only between two likes poles of a magnet.

For example North repels North and South repels south.

Attraction is evident between two unlike poles of a magnet. Attraction is also evident  between a magnet and a material that is magnetic. Attraction is therefor not a test for a magnet while  repulsion is a certain test for magnet.