Leviticus 23:6

The feast of unleavened bread. Closely connected with the Passover, yet distinct from it, was the Feast of Unleavened Bread, which followed. For practical purposes the two feasts were considered as one, and the names are often used interchangeably. But in purpose they were somewhat different. The Passover stood for deliverance (Ex. 12:13); the unleavened bread was reminiscent of the haste in which Israel left Egypt (Ex. 12:33, 39; Deut. 16:3). God was explicit as to the manner in which the Feast of Unleavened Bread should be celebrated (Ex. 12:15). Of it Paul later said, “Let us keep the feast, not with old leaven, neither with the leaven of malice and wickedness; but with the unleavened bread of sincerity and truth” (1 Cor. 5:8).

Leaven was to be entirely excluded. It represents malice and wickedness (1 Cor. 5:8), and false doctrine, as exemplified in the teachings of the Pharisees, the Sadducees, and the Herodians (Matt. 16:6, 12; Mark 8:15). The leaven of the Pharisees is greed and injustice (Matt. 23:14), a dog-in-the-manger spirit (v. 13), false zeal (v. 15), wrong estimates of spiritual values (vs. 16-22), omission of justice, mercy, and faith (v. 23), vain punctiliousness (v. 24), hypocrisy (vs. 25-28), intolerance (vs. 29-33), and cruelty (vs. 34-36). The leaven of the Sadducees is skepticism (Matt. 22:23) and a lack of knowledge of the Scriptures and of the power of God (v. 29). The leaven of the Herodians is flattery, worldly-mindedness, and hypocrisy (vs. 16-21), and plotting evil against God’s representatives (Mark 3:6).