Crown of glorying (stephanos kauchēseōs). When a king or conqueror came on a visit he was given a chaplet of glorying. Paul is answering the insinuation that he did not really wish to come.
At his coming (en tēi autou parousiāi). This word parousia is untechnical (just presence from pareimi) in 2Th 2:9; 1Co 16:17; 2Co 7:6.; 2Co 10:10; Phi 1:26; Phi 2:12. But here (also 1Th 3:13; 1Th 4:15; 1Th 5:23; 2Th 2:1, 2Th 2:8; 1Co 15:23) we have the technical sense of the second coming of Christ. Deissmann (Light from the Ancient East, pp. 372ff.) notes that the word in the papyri is almost technical for the arrival of a king or ruler who expects to receive his “crown of coming.” The Thessalonians, Paul says, will be his crown, glory, joy when Jesus comes.