A.T. Robertson Commentary 1 John 2:10

"He that loveth his brother abideth in the light, and there is no occasion of stumbling in him." — 1 John 2:10 (ASV)

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