Matthew 13 (31-32); Mark 4 (31) and Luke 13 (18-19) all contain what is referred to as “The parable of the mustard seed.” This parable is frequently used by Bible critics to point out that the Bible has errors. But does it really? The thing that critics key in on is that the Matthew and Mark versions of the parable contain Jesus stating that the mustard seed is “the smallest of all seeds.” These same critics are then quick to point out that other seeds in nature are in fact smaller than the common mustard seed. There are even seminary professors and preachers that admit this but reason it away. These persons side with the critics that Jesus is wrong here yet affirm that the purpose of the passage was to just give the idea that something small will grow into something large. But the conclusion to this way of thinking is that if Jesus is wrong here, where else might He be wrong?
The question we need to ask is what the definition of seeds is in Jewish agriculture of Jesus’ time. Sure we can force a 21st century definition of seed upon the text and conclude that under the microscope orchids, among other plants, produce far smaller seeds. But Jesus is not giving a botany lesson. He is relating to an agricultural people the seed they could go out and locally realistically purchase (and commonly would have) to plant as for use in their garden. Why not then would Jesus use Orchids as the smallest seeds? Well, for one it does not fit the context in that it needs to be a seed that is of the greater of all herbs (Matthew 13:32; Mark 4:32). Two as a tree it relates the ability of birds to come and nest in the branches. Orchids are thus not herbs and do not grow large enough to have branches that would support bird nests so as to illustrate the Gentiles ability to come in to the Church. Therefore the mustard seed is the smallest seed the people would know of as pertaining to growing in their local gardens, of being an herb, and being large enough to support birds.