A.T. Robertson Commentary Luke 21:30

"when they now shoot forth, ye see it and know of your own selves that the summer is now nigh." — Luke 21:30 (ASV)

Shoot forth (προβαλωσιν). Second aorist active subjunctive of προβαλλω, common verb, but in the N.T. only here and Ac 19:33.

Summer (θερος). Not harvest, but summer. Old word, but in the N.T. only here (Matthew 24:32).