Midrash su I Re 5:29

But behold it is written (Deut. 24, 26) Fathers shall not be put to death for the children, neither shall children be put to death for the fathers? R. Chiya b. Abba said in the name of R. Jochanan: "Rather let one word of the Torah become impotent, than have the Heavenly name publicly profaned." (II Sam. 21, 10) And Rizpah the daughter of Ayah took sack cloth, and spread it out for herself upon the rock, from the beginning of the harvest until water dropped down upon them out of heaven, and she suffered neither the birds of heaven to rest on them by day, nor the beasts of the field by night. Behold it is written (Deut. 21, 23) Then shall his body not remain all night on the tree. R. Jochanan in the name of R. Simon b. Jehozadak said: "It is worth while that one letter of the Torah become impotent, if only the Heavenly name should [through it] be sanctified publicly: [for, whoever passed by the corpse] asked: 'What is the nature of these? Are they not princes, and what [crime] have they committed?' Because they had raised their hands against self-made converts (not formally admitted),' [the reasons were given.] The inquirers then would remark: 'There is no other nation that is more fitting to be associated with than this (Israel); for, if to princes they gave such punishment how much more so to an ordinary man; and if they so protect self-made converts, how much more so will they protect real Israelites (duly admitted proselytes)?' The result therefrom was that Israel was increased by one hundred and fifty thousand [proselytes], as it is said (I King 5, 29) And there belonged to Solomon seventy thousand bearers of burdens, and eighty thousand stone cutters in the mountains." But perhaps these were Israelties? You cannot possibly think so, for it is written (Ib. 9, 22) Yet of the children of Israel did Solomon make no one a servant. But perhaps the above were merely salaried employees? We must therefore say that the above is inferred from here (II Chr. 2, 16) And Solomon numbered all the gerim (proselytes) that were in the land of Israel, etc., and they were found to be one hundred and fifty thousand. And he made of them seventy thousand bearers of burdens, etc. And was then the decree against the Gibeonites issued by David? Behold! Moses issued the decree, as it is written (Deut. 29, 10) from the hewer of the wood, etc. Moses merely decreed it for that generation, but David decreed it for all generations. Again has not Joshua decreed concerning them? For it is written (Josh. 9, 27) And Joshua appointed them only that day hewers of the wood, etc. Joshua's decree was only for the period during which the Temple existed, but David's decree was issued for the period beyond the destruction of the Temple.