Exegesis:
kai ‘and’ (the first word): here with the meaning ‘but,’ ‘yet.’
anabainei (cf. 4.7) ‘it grows.’
meizon pantōn tōn lachanōn ‘bigger than all the shrubs’: as in the previous verse the comparative ‘bigger than’ is used with the meaning ‘biggest of.’ The neuter meizon ‘bigger’ is due either to sperma ‘the seed is bigger’ implied in the statement, or to tōn lachanōn ‘of the shrubs’ which follows.
lachanōn (only here in Mark) ‘vegetable,’ ‘edible garden herb’ .
poiei kladous megalous ‘it makes large branches.’
poieō here means ‘produce,’ ‘send out.’
klados (13.28) ‘branch,’ ‘limb.’
hōste dunasthai … kataskēnoun (for the construction see 1.27) ‘so that they (the birds) are able to live.’
kataskēnoō (only here in Mark) ‘live,’ ‘dwell,’ ‘settle’: of birds, ‘nest.’ The saying about the birds nesting in the shade reflects O.T. passages such as Dan. 4.12 (cf. Ezek. 17.23; 31.6; Ps. 104.12).
tēn skian autou ‘its shade,’ i.e. of the grown mustard plant.
skia (only here in Mark) ‘shadow,’ ‘shade.’
Translation:
The Greek term translated here as shrubs refers primarily to large annuals. One should not render this as ‘trees of the forest’ (as in some translations, merely in order to emphasize the extent of growth of the plant). Where a language possesses a generic term for annuals (a not infrequent classification), one can make ready use of this word. In some instances, however, in order to use some relatively satisfactory equivalent, translators have used ‘plants that grow for a year’ (Highland Totonac).
For birds of the air see 4.4. A literal translation of this expression can be quite misleading. In one language in Latin America this phrase was taken to refer to the Holy Spirit, for it was understood to mean ‘doves from heaven,’ and since the dove is employed in Roman Catholic ritual as a symbol for the Holy Spirit, the meaning of the passage was entirely misconstrued. The meaning here is simply ‘field birds,’ ‘birds of the forest,’ or ‘undomesticated fowl.’
Nests in its shade must in some instances be more precise, i.e. ‘nests in its branches under its shade,’ or the use of ‘shade’ would imply nests on the ground beneath the plant.
Quoted with permission from Bratcher, Robert G. and Nida, Eugene A. A Handbook on the Gospel of Mark. (UBS Handbook Series). New York: UBS, 1961. For this and other handbooks for translators see here .