In "Why is YHWH translated LORD?" you said:
Some, such as the Jehovah's Witnesses, object to using LORD in place of YHWH. However, they are ignoring God's own translation of His name. For example, Jesus quotes Deuteronomy 6:5 in Matthew 22:37, "Jesus said to him, 'You shall love the LORD your God with all your heart, with all your soul, and with all your mind.'" Jesus used the Greek word kurios ("lord") to translate YHWH. This is done consistently in the New Testament, which is inspired by God. Hence, God has shown us that it is proper to translate YHWH as "Lord." The use of all capitals is a convention used by translators to indicate that YHWH is behind the word "Lord" and not the normal Hebrew word adhon.
Are you sure about this? Or could it be that Jesus actually used God’s name when quoting from the original Hebrew texts, however it was later changed to read LORD due to some translators following the same spurious reasoning of some this Rabbis you mentioned earlier? Remember, what you quoted from above is a version or translation of the original text, not the original Hebrew text. Would it be reasonable to believe that Jesus, who condemned the Rabbis for invalidating the word of God would himself follow their tradition in replacing God’s name with Lord or God when the original inspired text used Jehovah’s name? Matthew 15:6-9 – Jesus said of these religious leaders, “And so you have made the word of God invalid because of your tradition. You hypocrites, Isaiah aptly prophesied about you, when he said, ‘This people honors me with their lips, yet their heart is far removed from me. It is in vain that they keep worshiping me, because they teach commands of men as doctrines.’” It would be a grave mistake to think Jesus would follow such a course, especially when he says that he made God’s name known and would make it known. John 17:6,26.
There is readily available evidence that Jesus and his disciples would have come across Jehovah’s name in the texts that they used. It is widely known that Matthew’s gospel was originally written in Hebrew. An inspired writer of scripture would not have followed the Rabbis tradition of hiding Jehovah’s name where he originally placed it, (i.e. in the scripture you cited in Deuteronomy). In addition, some very old fragments of the Septuagint that existed in Jesus day have survived to our day, and guess what, they contain Jehovah’s name. Don’t take my word for it. Please reference The New International Dictionary of New Testament Theology, (Volume 2 Page 512).
While there is a persistent myth that Matthew was originally written in Hebrew, the myth is easily shown to be false. See "Was Matthew originally written in Hebrew or Aramaic?"
But this is actually a distraction. Are you prepared to argue that the rest of the New Testament was altered? I know of no one arguing that Mark was originally written in Hebrew, but Mark says, "Jesus answered him, "The first of all the commandments is: 'Hear, O Israel, the LORD our God, the LORD is one" (Mark 12:29). This a quote of Deuteronomy 6:4. Or how about "So he answered and said," 'You shall love the LORD your God with all your heart, with all your soul, with all your strength, and with all your mind,' and 'your neighbor as yourself'"" (Luke 10:27), which is a quote of Deuteronomy 6:5). Or, "Because finding fault with them, He says: "Behold, the days are coming, says the LORD, when I will make a new covenant with the house of Israel and with the house of Judah"" (Hebrews 8:8), a quote of Jeremiah 31:31). The Holy Spirit consistently used "Lord" for yhwh when the New Testament books were written.
The New Testament, like the Old Testament, was written by men inspired by the Holy Spirit, "for prophecy never came by the will of man, but holy men of God spoke as they were moved by the Holy Spirit" (II Peter 1:21). The word selection was God's, not mans. "These things we also speak, not in words which man's wisdom teaches but which the Holy Spirit teaches, comparing spiritual things with spiritual" (I Corinthians 2:13). It was God who decided that the best translation of the Hebrew word yhwh was kurios in Greek, which we translate as "Lord."
You wish to claim that someone altered the text at a later point. So where is your proof? Where are the manuscripts showing an alteration so we can trace its history. A wishful desire of the Jehovah's Witnesses' part does not constitute proof.
Your quote of Matthew 15:6-9 does not prove that the Jews people had altered God's Word. Jesus was discussing their traditions which conflicted with God's laws, not alterations in the actual text.
You claim the Septuagint used "Jehovah" in its text. Here is Deuteronomy 6:4 from the Septuagint: ?a? ta?ta t? d??a??µata ?a? t? ???µata ?sa ??ete??at? ?????? t??? ????? ?s?a?? ?? t? ???µ? ??e????t?? a?t?? ?? ??? ????pt?? ????e ?s?a?? ?????? ? ?e?? ?µ?? ?????? e?? ?st?? In case you don't read Greek, I highlighted the word in question. It is the Greek word kurios, which is translated "Lord." Neither yhwh or Jehovah appears in the text. But whether it did or not would not make a difference since the Septuagint is a translation.
All you have is an unsupported claim.