ISB ~ Revelation 2 v10

ten days:Possibly an allusion to the pagan rites of Niobe, practiced in Smyrna, whose devotees underwent ten days of mourning.

• Daniel and his friends were also tested for ten days lest they compromise their faith by eating foods contaminated by idolatry (Dan 1:8-14).

the crown of life:Means the crown that is (eternal) life. See note on Jas 1:12.