John Lightfoot on Luke 10:26

[How readest thou?] An expression very common in the schools, What readest thou? when any person brought a text of Scripture for the proof of any thing. The Rabbins have a tradition, that the disease of the squinancy came into the world upon the account of tithes. (The Gloss hath it: "For eating of fruits that had not been tithed.") "R. Eliezer Ben R. Jose saith, 'It was for an evil tongue.' Rabba saith, and it is the saying also of R. Joshua Ben Levi, What readest thou? The king shall rejoice in God; every one that sweareth by himself shall glory: for the mouth of them that speak lies shall be stopped." And a little after, upon another subject: "R. Simeon Ben Gezirah saith, What or how readest thou? If thou know not, O thou fairest among women, go thy way forth by the footsteps of the flock": Canticles 1:8.

We will not be very curious in inquiring whether our Saviour used the very same form of speech, or any other. In this only he departs from their common use of speech, in that he calls to another to allege some text of Scripture; whereas it was usual in the schools that he that spoke that would allege some place himself.