Exegesis:

to de paidion ēuxanen kai ekrataiouto plēroumenon sophia ‘the child grew up and became strong, being filled with wisdom,’ conclusion of the preceding narrative. ekrataiouto is best understood as referring to mental and moral growth because (1) this area of meaning is most widely attested in the Septuagint and other Koine texts, and (2) the similarity between this verse and 1.80 suggests the same meaning on both places rather than different meanings. Hence it is better to take ekrataiouto and plēroumenon sophia as semantically belonging together. Then the latter phrase either defines ekrataiouto (‘he became strong because he was being filled with wisdom’) or complements it (‘he became strong and was being filled with wisdom,’ implying that ‘becoming strong’ and ‘being filled with wisdom’ are closely related concepts), preferably the latter.

plēroumenon sophia ‘being filled with wisdom’ may be derived from the idiom ‘being full of the spirit’ (cf. on 4.1; also Acts 6.3, Eph. 5.18), and it means that the wisdom becomes more and more the dominating power of his life.

sophia ‘wisdom,’ here simply “insight in the will and rule of God” (Grundmann), which is not man’s own achievement but imparted by God.

charis theou ēn ep’ auto ‘the blessing of God was upon it’; auto (acc.) refers to to paidion ‘the child.’ For einai epi cf. on v. 25. charis may here refer either to God’s favour, or to God’s grace as a source of blessing, preferably the latter and the phrase is best understood in analogy to ‘the Holy Spirit was upon him’ (v. 25), and as indicating the origin of his growth in wisdom.

Translation:

And (for Gr. de) here introduces a change from the parents, who were in focus in v. 39, to the child; hence renderings like ‘as to the child, its bigness increased’ (Javanese).

Grew, cf. on 1.80.

Became strong, to be understood figuratively, of spiritual, mental strength (see Exegesis). In some languages (e.g. Bahasa Indonesia, Tboli) the usual term for ‘strong’ does not allow the required figurative extension of meaning; hence, ‘his mind developped’ (Bahasa Indonesia RC). Cf. also on “became strong in spirit” in 1.80.

Filled with wisdom, or, ‘had much wisdom,’ ‘very wise’ (Tboli), ‘was becoming abundant in wisdom’ (Telugu). Wisdom has been rendered, ‘(big) mind’ (Amganad Ifugao, Tabasco Chontal), ‘heart thinking’ (Bulu, Yamba), ‘cleverness of heart’ (Tae’). The concepts ‘slyness,’ ‘cleverness,’ ‘knowledge,’ ‘magic skill,’ and ‘wisdom’ sometimes are not clearly distinguished; terms may overlap considerably or even coincide for some or all of these concepts, and therefore require careful handling. This is shown e.g. by the revision in Batak Toba where ‘slyness/cleverness’ was changed into ‘true mind,’ or in Bahasa Indonesia, hikmat (an Arabic borrowing, meaning ‘wisdom’ but also ‘magic skill/charm’) changed into a term indicating ‘practical wisdom/prudence,’ and even ‘policy.’ One should not choose a term that refers exclusively, or primarily, to book learning or keen intellect.

And the favour of God was upon him, or, changing the syntactic structure, ‘and (or, because) God gave him favour/grace/blessing, or, favoured/graced/blessed him.’ For favour, or, ‘grace,’ see on 1.30, for ‘bless(ing)’ on 1.42 sub (1).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.