Initial Research on Judges 1:6-7

When Adoni-Bezek ran away, they chased him and captured him. Then they cut off his thumbs and big toes. Adoni-Bezek said, “Seventy kings, with thumbs and big toes cut off, used to lick up food scraps under my table. God has repaid me for what I did to them.” They brought him to Jerusalem, where he died. (Judges 1:6-7 NET Bible)

καὶ εἶπεν Αδωνιβεζεκ ῾Εβδομήκοντα βασιλεῖς τὰ ἄκρα τῶν χειρῶν αὐτῶν καὶ τῶν ποδῶν αὐτῶν ἀποκεκομμένοι ἦσαν συλλέγοντες τὰ ὑποκάτω τῆς τραπέζης μου· καθὼς οὖν ἐποίησα, οὕτως ἀνταπέδωκέν μοι ὁ θεός. καὶ ἤγαγον αὐτὸν εἰς Ιερουσαλημ, καὶ ἀπέθανεν ἐκεῖ (Judges 1:7 LXX).

So, in this case, it seems that God did approve of the mutilated toes and thumbs. At least Adoni-Bezek didn't get all his fingers and toes severed. More seriously, we see the law of lex talionis in motion here: eye for eye and tooth for tooth. Ellicott's Commentary marshals other verses that make similar proclamations. For example:

And Samuel said, "As your sword has made women childless, so shall your mother be childless among women." And Samuel hacked Agag to pieces before the LORD in Gilgal. (1 Samuel 15:33 ESV)

Concerning Judges 1:7, Ellicott remarks:

The "seventy" kings may have been the rulers of the towns which Adoni-bezek had taken in extending the territory of Bezek. Josephus says seventy-two kings (Antt. v. 2, § 2), and this common variation is found in some MSS. of the LXX. The Persians treated their Greek captives in this way (Curtius, v. 5,6). Mutilation in the East was so common that it was hardly accounted cruel (Xen. Anab. i. 9-13).

Addendum: While Jehovah God could have decreed Adoni-Bezek's fate, it's also possible that God merely permitted him to undergo this fate.