Ἰωάννην 8·6 τοῦτο δὲ ἔλεγον πειράζοντες αὐτόν, ἵνα ἔχωσιν κατηγορεῖν αὐτοῦ. ὁ δὲ Ἰησοῦς κάτω κύψας τῷ δακτύλῳ κατέγραφεν εἰς τὴν γῆν. 7 ὡς δὲ ἐπέμενον ἐρωτῶντες αὐτόν, ἀνέκυψεν καὶ εἶπεν αὐτοῖς· ὁ ἀναμάρτητος ὑμῶν πρῶτος ἐπ᾿ αὐτὴν βαλέτω λίθον. 8 καὶ πάλιν κατακύψας ἔγραφεν εἰς τὴν γῆν.
And they were saying this, testing him, that they may have something to accuse him. And Jesus bent down and was writing on the ground. And when they were continuing to question him, he stood up and said to them, “The sinless one among you must throw the first stone at her.” And he bent down and was writing on the ground again. John 8:6-8
Here is a final point about this passage. βαλέτω, “must throw”, is a third person imperative. In the second person, it is used as a command or demand. In the third person, it can be translated “let him throw”. In english, that sounds a little more like giving permission as opposed to a command. Wallace says (Greek Grammar Beyond the Basics) that “he must” is closer to the force of the 3rd person imperative than “let him”. I also think that it demonstrates Jesus’ authority in the passage.