It is, indeed, the least of all seeds, but when it has grown, it is greater than all the plants, and it becomes a tree, so much so that the birds of the air come and dwell in its branches.
Other versions
King James Version
Which indeed is the least of all seeds: but when it is grown, it is the greatest among herbs, and becometh a tree, so that the birds of the air come and lodge in the branches thereof.English Standard Version
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."New International Version
Though it is the smallest of all your seeds, yet when it grows, it is the largest of garden plants and becomes a tree, so that the birds of the air come and perch in its branches."