For the proverbe seith that "manye smale maken a greet."
Modern English:
For the proverb says that "Many small make a great."

– Geoffrey Chaucer

The Canterbury Tales, The Parson’s Tale. The tale is more of a sermon on sin penance and confession. In this quote the Parson is saying that the more a person burdens their soul with venial sins, the more they are inclined to fall into mortal sin.