The word is a noun, meaning a gift. See Joh 4:10; Act 2:38; Rom 5:15. The accusative often adverbially as here; as a gift, gratis. Comp. Mat 10:8; Rom 3:24; Rev 21:6.
Labor and travail
See on 1Th 1:3.
Be chargeable (ἐπιβαρῆσαι)
Po. Better, burden. By depending upon them for pecuniary support. Comp. 1 Corinthians 9:3-18, and see on 1Th 2:6.