Exegesis:
ti hoti ezēteite me ‘why is it that you were looking for me?’; ti hoti, with ellipsis of estin ‘is,’ ‘why (is it) that?,’ stronger than a simple ti, or dia ti ‘why’ (cf. Acts 5.4, 9 with Lk. 5.30; 19.23, 31, 33; 22.46), here expresses surprise because Jesus’ parents did not know where to find him.
ouk ēdeite ‘did you not know.’
oida ‘to know’; when used with an object, person or thing, synonymous with ginōskō (cf. Moulton-Milligan 439).
hoti en tois tou patros mou dei einai me ‘that it is necessary that I am in my Father’s house,’ or ‘engaged in my Father’s business.’ The context requires us to interpret ta tou patros mou (lit. ‘the (things) of my father’) as ‘my father’s house,’ for which a sufficient number of parallels may be quoted; the place of en tois tou patros mou at the beginning of the clause indicates emphasis.
dei impersonal ‘it is necessary,’ here followed by an accusative and infinitive. Here it expresses a compulsion of duty.
Translation:
How is it that you sought me, or, ‘how did you come (or, need) to look for me’ (An American Translation, Batak Toba). The point of the question is that, as Joseph and Mary should have expected Jesus to be in the temple, there was no reason for them to run about seeking him. To make this clear Tboli has, ‘why did you look in a different place for me?’— You here may have to be specified, e.g. ‘mother and father’ (Balinese, where the use of the pronoun would be unnatural and impolite from a son addressing his parents). Elsewhere the pronoun is omitted, ‘why seek me’ (Sundanese, probably for similar reasons).
I must, or, ‘I have to,’ ‘it is proper that I,’ or, ‘as to me, not I not’ (Toraja-Sa’dan), which often can also be used in cases like 4.43 and 9.22.
In my Father’s house, or, ‘at my father’s’ (Balinese, expressing the meaning of the phrase without using a term for ‘house,’ as the Greek does). When ‘house’ must be added, the rendering will usually coincide with that of “(my Father’s/thy) house” in John 2.16f, cf. also “house (of God)” in Lk. 6.4. Yet it can be argued that the expression in the present verse is more intimate. For this reason, probably, Javanese here uses the normal word for the house of a person of rank, but in Lk. 6.4, John 2.16f the more literary ‘mansion’ (also part of its rendering of “temple”). A rendering like ‘in that which is my Father’s,’ is an attempt to imitate the vagueness, which the Greek phrase has in our ears (but probably had not for Luke’s readers or hearers); usually it implies the use of an expression that is uncommon or will not easily be understood in the right sense by the hearer or reader. My Father, here referring not to a human father but to the heavenly Father. In languages that differentiate according to rank the fact that both Jesus and the persons he addresses, his parents (here), or his followers (22.29; 24.49), acknowledge this heavenly Father as their God, usually leads to the use of an honorific term. Balinese, for instance, employs the term by which a prince would refer to his royal father in a conversation with his father’s subjects. Other occurrences of Father in this meaning: 6.36; 9.26; 10.21f; 11.2, 13; 12.30; 22.42; 23.34, 46.
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.