Exegesis:

hoti pas ho hupsōn heauton tapeinōthēsetai ‘for everyone who exalts himself will be humbled.’ For hupsoō cf. 1.52. For tapeinoō cf. on 3.5; here it is used in a figurative sense. The agent of tapeinōthēsetai is God, since the saying and the preceding parable are to be understood as referring to a religious attitude.

ho tapeinōn heauton hupsōthēsetai ‘he who humbles himself will be exalted.’ For the agent of hupsōthēsetai see above.

Translation:

One may have to shift to an ‘if’ clause (cf. 9.24), and/or to an active form, ‘God will humble him, … exalt him’ (cf. 6.37).

Exalts himself … humbles himself, or, ‘tries to reach a high position (or, makes his own power great, Kekchi)…, accepts (or, is ready to be in) a low position.’

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.