when, &c. = no longer bearing it, i.e. able to bear it.
no longer. Greek. meketi.
forbear = bear. See 1Co_9:12.
thought it good = were well pleased. Same as "were willing" (1Th_2:8).
Athens. See Act_17:15, Act_17:16. When Silas and Timothy joined Paul, he and Silas must have agreed to dispatch Timothy to Thessalonica, and then Silas must have departed on some other mission. See in 1Th_3:5 the change from "we" to "I".