Mt. here brings together material (a) found scattered in Lk., (b) peculiar to himself.
Matthew 5:13-16. Salt and Light. Good men are not only rewarded in the coming age, they help the world now and save it from both insipidity and corruption. To appreciate the value of salt one must live in a land where it is rare, and much more highly prized than sugar. The second clause of Matthew 5:13 (cf. Mark 9:50; Luke 14:34) was a current proverb; salt was heavily taxed, and therefore often so adulterated as to lose its salinity. With the third clause cf. Hebrews 6:4-8; Hebrews 10:26-29, and the fate of Judas Iscariot. With Matthew 5:14 cf. Romans 2:19 (Jews), Php_2:15, Acts 13:47; John 8:12. The connexion between the two parts of Matthew 5:14 is the conspicuousness of an elevated character. Ideally a true disciple (Matthew 5:15) cannot hide his light (the word translated bushel means a measure holding about a peck); actually it is only too possible (Matthew 5:16). In Matthew 5:15 the light may be the influence of preaching (cf. Luke 8:16; Luke 11:33); in Matthew 5:16 it is the influence of deeds (cf. 1 Peter 2:12).