When the mustard plant is fully grown it is the largest of the common garden crops and can reach a height of up to three meters. In that case it is not unnatural to speak of it as a tree. A tree is a familiar image for a mighty realm that shelters its dependents (Ezekiel 17:23, Ezekiel 31:6; Daniel 4:12, Daniel 4:21).1
32 C'est la plus petite de toutes les semences; mais, quand il a poussé, il est plus grand que les légumes et devient un arbre, de sorte que les oiseaux du ciel viennent habiter dans ses branches.