MUSTARD
His seed is mentioned as something extremely small, but to which the faith of the apostles did not even reach (Lk. 17:6).
The kingdom of God is also compared to this small seed, which nevertheless grows into a tree large enough for birds to find shelter in its branches.
Various assumptions have been made about which plant is mentioned here. The one that best corresponds to the description is “sinapis nigra”, a mustard plant common in Palestine.
Its seeds are extremely small, and it grows into a “tree” shrub more than three meters high, so that small birds can take refuge in its branches.
There is also the “salvadora persica”, which grows to a greater height. The teaching of this parable is that the kingdom of God would be magnified on earth, so that Satan’s emissaries could find refuge under its shadow (cf. Mt. 13:31, 32 and vv. 4, 19). (See also YEAST.)
It is about growth, but, as in other parables given in the same context (Mt. 13), it teaches growth with corruption due to the action of the enemy.