Luke has John give this menacing saying that can be found almost word for word in Matthew, chapter 3:12. Thus, this might be a Q source saying, since it is not found in Mark or John. Luke has God, the Lord, as a farmer at harvest time. Luke had John say that this famer has his winnowing fork ready in his hand (οὗ τὸ πτύον ἐν τῇ χειρὶ αὐτοῦ). He was going to clear the threshing floors (διακαθᾶραι τὴν ἅλωνα αὐτοῦ). He was going to gather his wheat into his barn or granary (καὶ συναγαγεῖν τὸν σῖτον εἰς τὴν ἀποθήκην αὐτοῦ). He would then burn up the leftover chaff (τὸ δὲ ἄχυρον κατακαύσει) with an everlasting or unquenchable fire (πυρὶ ἀσβέστῳ). This last phrase was a little different than that of Matthew. Nevertheless, this was a clear warning against the useless ones, who like chaff, would burn in an unstoppable fire.
Once again, there is a common source for John’s menacing saying between Luke, chapter 3:17, and Matthew, perhaps Q. God, the Lord of this farmer, has the winnowing fork in his hand (οὗ τὸ πτύον ἐν τῇ χειρὶ αὐτοῦ). He was going to clear the threshing floors (καὶ διακαθαριεῖ τὴν ἅλωνα αὐτοῦ,). He was going to gather his wheat into his barn in the granary (καὶ συνάξει τὸν σῖτον αὐτοῦ εἰς τὴν ἀποθήκην). The leftover chaff would be burned with an everlasting fire that could not be put out (καὶ συνάξει τὸν σῖτον αὐτοῦ εἰς τὴν ἀποθήκην). This was a warning against the useless ones who would burn in an unstoppable fire.