Abideth (μενε). Present active indicative, continues in the light and so does not interrupt the light by hating his brother.

Occasion of stumbling (σκανδαλον). See on Matthew 13:41; Matthew 16:23 for this interesting word. It is a stumbling block or trap either in the way of others (its usual sense), as in Matthew 18:7, or in one's own way, as is true of προσκοπτω in John 11:9 and in verse 1. John 2:11 here. But, as Westcott argues, John may very well have the usual meaning here and the other in verse 1. John 2:11.