Critics often point to Jesus’ words about the mustard seed and claim He made a scientific mistake. In the Gospel accounts Jesus says:
“It is like a grain of mustard seed, which, when sown on the ground, is the smallest of all the seeds on earth.” (Mark 4:31)
“The kingdom of heaven is like a grain of mustard seed that a man took and sowed in his field. It is the smallest of all seeds, but when it has grown it is larger than all the garden plants and becomes a tree, so that the birds of the air come and make nests in its branches.” (Matthew 13:31–32)
The objection is simple: the mustard seed is not literally the smallest seed in existence. It is about 1-2mm in size. Botanists, those who study plants, can point to several seeds that are smaller.
Several known seeds are smaller:
| Seed | Approximate Size (smallest to largest) |
|---|---|
| Orchid seed | 0.05–0.5 mm long (many are nearly dust-like) |
| Begonia seed | About 0.2–0.3 mm |
| Petunia seed | About 0.5 mm |
| Amaranth seed | Around 0.9–1.3 mm |
| Mustard seed | Around 1–2 mm |
So did Jesus get it wrong? Not at all. The supposed dilemma largely disappears when we carefully read the text and understand the context in which Jesus was speaking.
Jesus Was Talking About Seeds Sown in the Ground
Notice Mark’s wording carefully:
“…mustard seed, which, when sown on the ground, is the smallest of all the seeds on earth.” (Mark 4:31)
“The kingdom of heaven is like a grain of mustard seed that a man took and sowed in his field. It is the smallest of all seeds…” (Matthew 13:31–32)
The Greek word gē (γῆ) can mean “earth”, “land,” “ground,” or “soil” depending on the context. In Mark 4 the context is agricultural. Jesus is discussing seeds being planted in the ground. The focus is not every seed on the planet but the seeds relevant to farming and gardening in the land where His audience lived.
First-century Jewish farmers did not cultivate orchid seeds from distant tropical regions. Ancient Israelites did not deliberately sow orchid seeds. While several dozen orchid species are native to the region, ancient agriculture focused on grains, legumes, and orchard trees. Because orchid seeds are extremely microscopic (dust-like) and require specialized fungi to germinate, they were not cultivated or propagated for food or medicine in antiquity. However, they did cultivate mustard plants. Among the seeds commonly sown by Palestinian farmers, the mustard seed was proverbially known for its small size.
Jesus was speaking directly to the experience of His audience. From their perspective, there was no smaller seed that was cultivated that grew to such a size.
People today still speak proverbially in some cases. We speak of “sunrise” and “sunset” but those are scientifically and literally incorrect. Technically, according to modern astronomy, the sun is not rising or setting. The Earth is rotating. Yet nobody accuses weather forecasters of scientific ignorance when they announce a sunrise time. They are using ordinary observational language—describing the world as it appears from a human perspective.
Jesus did exactly the same thing. He was not delivering a scientific lecture about the study of plants. He was speaking to ordinary people who were familiar with everyday farming experiences. He talked about the kingdom of God using everyday experiences they understood immediately.
Imagine if He had said:
“I want to illustrate how small My kingdom appears now and how astonishingly large it will become. So let me use the example of an orchid seed—a seed none of you cultivate, most of you have never seen, which requires specialized fungal relationships to germinate, and which doesn’t even grow into a particularly large plant.”
That would have produced no surprise and no impact.
Instead, Jesus chose an example His audience knew intimately: the mustard seed. It was proverbially tiny in everyday Jewish life, yet it grew into a remarkably large garden plant. The point of the parable is not to provide a botany lesson about the smallest seed on earth. The point is to create a vivid contrast between an unimpressive beginning and a surprisingly large outcome. Christ knew His audience. Instead, He chose an example every farmer, gardener, and villager knew. They had seen mustard seeds. They had planted them. They knew how surprisingly large the resulting plant could become.
Many critics focus entirely on the phrase “smallest of all seeds” and ignore the rest of the sentence.But Jesus continues:
“But when it is sown, it grows up and becomes greater than all herbs.” (Mark 4:32)
This reveals His actual concern. The subject of the parable is the Kingdom of God. The kingdom begins small and seemingly insignificant. Yet it grows into something enormous, influential, and welcoming. The birds nesting in its branches symbolize people finding refuge and blessing within God’s kingdom.
Why the Mustard Seed Was the Perfect Illustration
Even if some seeds were technically smaller, they would not have served Jesus’ purpose. The mustard seed is unique because of the contrast between its tiny beginning and its dramatic growth. Many of the seeds that are smaller than mustard seeds produce plants that remain relatively small. But the mustard plant can grow into a remarkably large shrub—sometimes reaching heights that made it appear tree-like in ordinary speech.
Jesus needed one seed that emphasized both:
- An extremely small beginning.
- An unexpectedly large result.
The mustard seed accomplished both goals perfectly.
If He had chosen a smaller seed that grew into a tiny plant, the illustration would have lost its force. The entire point is the disproportion between the beginning and the outcome. The mustard seed is not merely small; it is small in a way that leads to surprisingly large growth. That is exactly what Jesus wanted to communicate about His kingdom.
Turning the Tables on The Quran
If Muslims appeal to such argumentation, then they have a dilemma of their own to address. In Surat al-Fath 48:29 says:
Surah 48:29 – That is their likeness in the Torah, and their likeness in the Gospel: as a seed that puts forth its shoot, and strengthens it, and it grows stout and rises straight upon its stalk, pleasing the sowers, that through them He may enrage the unbelievers.
The only Gospel that contains such a parable is found only in the Gospel of Mark, chapter 4:26-29
Mark 4:26-29 – 26 And He said, “The kingdom of God is as if a man should scatter seed on the ground, 27 and should sleep by night and rise by day, and the seed should sprout and grow, he himself does not know how. 28 For the earth yields crops by itself: first the blade, then the head, after that the full grain in the head. 29 But when the grain ripens, immediately he puts in the sickle, because the harvest has come.”
Abdullah Yusuf Ali had no problem admitting in his commentary , “The Holy Quran – Text, Translation and Commentary”, p. 1586 source:
The similitude in the Gospel is about how the good seed is sown and growsgradually, even beyond the expectation of the sower: “the seed should spring and growup, he knoweth not how; for the earth bringeth forth fruit of herself; first the blade, thenthe ear, after that the full corn in the ear”: Mark. iv. 27-28. Thus Islam was preached
Maududi, in his commentary on the Quran, “The meaning of the Quran (tafhim al-Quran)” volume 5, p.67, footnote 56, he says concerning Q48:29:
56 This parable is found in a sermon of the Prophet Jesus that has been reported in the New Testament, thus:
“And he said, So is the kingdom of God, as if a man should east seed into the ground: And should sleep, and rise night and day, and the seed should spring and grow up, he knoweth not how. For the earth bringeth forth fruit of herself; first the blade, then the ear, after that the full corn in the ear. But when the fruit is brought forth, immediately he putteth in the sickle, because the harvest is come. And he said, Where unto shall we liken the kingdom of God? or with what comparison shall we compare it? It is like a grain of mustard seed, which, when it is sewn in the earth, is less than all the seeds that be in the earth: Hut when it is sown, it groweth up, and becometh greater than all herbs, and shouted out great branches; so that the fow is of the air may lodge under the shadow of it.” The last portion of this sermon is also found in Matthew, 13:31-32.
In other words, if the mustard seed is really a fatal problem for Mark’s Gospel, then the Quran has its own problem: it appeals to and confirms a parable found in the very Gospel that Muslims claim cannot be trusted. That is the Islamic dilemma all over again.