Luke continued with a diatribe against the Pharisees. Luke indicated that the crowd gathered by the thousands (Ἐν οἷς ἐπισυναχθεισῶν τῶν μυριάδων τοῦ ὄχλου), so that they trampled on one another (ὥστε καταπατεῖν ἀλλήλους). This was the first mention of a problem with crowd control. Jesus then began first to speak to his disciples (ἤρξατο λέγειν πρὸς τοὺς μαθητὰς αὐτοῦ πρῶτον). He told them that they should be aware (Προσέχετε ἑαυτοῖς) of the yeast (ἀπὸ τῆς ζύμης) that is the hypocrisy (ἥτις ἐστὶν ὑπόκρισις) of the Pharisees (τῶν Φαρισαίων). This saying about the yeast of the Pharisees can be found in Mark, chapter 8:16, and Matthew, chapter 16:6, but there are slight differences. Mark and Luke did not mention the Sadducees, but Matthew did. Matthew said that Jesus told his disciples to watch out for the yeast of the Pharisees and Sadducees. Matthew had a clear rebuff of both these groups and their growing yeast, leaven, or power that was expanding, but there was no mention of the Scribes. For Mark and Matthew, this discussion took place about bread on a boat trip. The disciples discovered that they had no food when they landed on the other side of the Sea of Galilee. However, Mark said that it took place while they were still in the boat. Mark was the only one to mention Herod, the Roman appointed political leader in Galilee. Mark said that Jesus cautioned or instructed his disciples. They were to watch out for and be aware of the yeast of the Pharisees and the yeast of Herod. This was a clear rebuff of both the Pharisees and Herod. Their growing yeast, leaven, or power was expanding. Here, it is a simple warning against the Pharisees only. Do you know anybody who is a hypocrite?
Now this saying about the yeast of the Pharisees and Sadducees can be found in Mark, chapter 8:15, and Luke, chapter 12:1, but there are slight differences. Mark and Luke did not mention the Sadducees. Jesus told his disciples (ὁ δὲ Ἰησοῦς εἶπεν αὐτοῖς) to watch out for and be aware (Ὁρᾶτε καὶ προσέχετε) of the yeast (ἀπὸ τῆς ζύμης) of the Pharisees and Sadducees (ἀπὸ τῆς ζύμης). Matthew has this as a clear rebuff of both these groups and their growing yeast, leaven, or power that was expanding. Like earlier in this chapter, there was no mention of the Scribes. The Pharisees were a political party, a social movement, and a religious school of thought that followed the Law of Moses, but with a number of oral traditions. They had they own expert explanations of Jewish law that sometimes appeared to be hypocritical or arrogant, with a form of Judaism that extended beyond the Temple. The Sadducees, on the other hand, were generally aristocratic priestly officials, tied to the Temple and ritual purifications. They were less concerned about oral traditions, so that they might have been political religious rivals to the Pharisees. However, Jesus warned his disciples against both groups.
“Seven days you shall eat unleavened bread. On the first day you shall remove leaven from your houses, for whoever eats leavened bread from the first day until the seventh day shall be cut off from Israel. On the first day you shall hold a solemn assembly, and on the seventh day a solemn assembly. No work shall be done on those days. Only what everyone must eat, that alone may be prepared by you. You shall observe the feast of unleavened bread, for on this very day I brought your companies out of the land of Egypt. You shall observe this day, throughout your generations, as a perpetual ordinance. In the first month, from the evening of the fourteen day until the evening of the twenty-first day you shall eat unleavened bread. For seven days no leaven shall be found in your houses. For whoever eats what is leavened shall be cut off from the congregation of Israel, whether an alien or a native of the land. You shall eat nothing leavened. In all your settlements you shall eat unleavened bread.”
For seven days you would eat unleavened bread. On the first day, you had to remove all the leaven from your house. If you ate leavened bread during this time, you were cut off from Israel. There is a solemn assembly on the first and seventh day, when no work was done. However, you could prepare meals. This is another perpetual ordinance that takes place after Passover in the spring time, from the evening of the fourteen day until the evening of the twenty-first day.
Leaven and unleavened bread becomes a big deal. What is this leaven, and why leave it out? Leaven is some kind of yeast that makes bread rise and makes it fluffy. Apparently, it takes longer to make leaven bread since you cook it longer. This unleavened bread is some kind of flat bread. This controversy carried over to Christianity about the use of regular fluffy bread or unleavened flat wafers in the Eucharistic Communion.