Josh 5:2 in the KJV (following the MT) reads:
At that time the Lord said unto Joshua, Make thee sharp knives, and circumcise again the children of Israel the second time.
The LXX reads a bit differently. The Greek reads:
ὑπὸ δὲ τοῦτον τὸν καιρὸν εἶπεν κύριος τῷ Ἰησοῖ ποίησον σεαυτῷ μαχαίρας πετρίνας ἐκ πέτρας ἀκροτόμου καὶ καθίσας περίτεμε τοὺς υἱοὺς Ισραηλ
The NETS translates the above thusly:
Now about that time, the Lord said to Iesous, "Make for yourself flint knives out of sharp rock, and sit down, and circumcise the sons of Israel."
Commenting on this and other variants between the MT and LXX, Reformed scholar Karl Deenick wrote:
The situation is complicated by textual differences between the LXX and the MT. But there are good reasons for preferring the MT. First, it seems strange in the LXX for God to command circumcision to be done while sitting down, given there is no interest elsewhere in Scripture regarding the posture for circumcision. Second, the LXX displays a number of signs of carelessness and amateurish translation: it lists the time spent in the desert as forty-two years rather than the usual forty (Graeme Auld, Joshua: Jesus Son of Naue in Codex Vaticanus [2004], 126); it names the desert as the Madbaritite desert (tē erēmō tē Madbaritidi), which seems to be an example of dittography combined with a total misunderstanding of the Hebrew language (Robert G. Boling, Joshua: A New Translation with Notes and Commentary [1982], 193; cf. Auld 2004:126); and the use of dio in v. 6 makes no sense: ‘For forty-two years Israel wandered in the Madbaritite desert, on account of which [dio] many of those warriors who had come out from the land of Egypt were uncircumcised’ (my tr.). How is it that forty-two years in the wilderness could have led to the prior uncircumcision of the adult males? Third, the LXX is inconsistent. Verse 7 recapitulates the message thus far, but instead of saying that Joshua circumcised both those who were born on the way and those who came out of Egypt (as it does in vv.4-5), it simply says that Joshua circumcised those born on the way. The latter being exactly what the MT says. Fourth, the LXX displays evidence of theologizing. ‘Purified’ (perikathairō; v. 4) is used in the place of ‘circumcised’ (see similarly, the LXX of Lev. 19:23 and Deut. 30:6; cf. Ibid. 126). But although circumcision is mentioned in the same context as uncleanness is in Lev. 12, circumcision and uncleanness are not strongly linked until the prophets (e.g. Isa. 52:1). It seems more likely that a later editor would have introduced rather than removed such a theologically freighted word. Fifth, the MT displays greater overall coherence. The MT plays on the terms tmm and ṥb’ (on which see below). Moreover, a comparison of the differing messages of the two versions proves enlightening. The key difference in the LXX is that those who came out from Egypt were also uncircumcised. This implies that the ‘reproach of Egypt’, and the chief obstacle to entering the land, was the uncircumcision of the men while they were in Egypt. This is possibly confirmed by v. 6 of the LXX, where ‘those who disobeyed the commands of God’ is set up in apposition to ‘they were uncircumcised, many of the warriors who came up out of Egypt, those who disobeyed the commands of God’ (my tr.). The implication is that their disobedience chiefly consisted of their failure to circumcise themselves and their children. In contrast, the only disobedience that the MT mentions is that those who came out of Egypt did not listen to the voice of Yahweh. Moreover, in the LXX it is the uncircumcised who die in the wilderness, while in the MT it is the circumcised who die in the wilderness and do not enter the land! It could plausibly be argued then that the MT represents the harder reading since it is those who possess the sign of the promise who fail to enter the land. (Karl Deenick, Righteous by Promise: A biblical theology of circumcision [New Studies in Biblical Theology 45; London: Apollos, 2018], 67 n. 24)
