'Ought' in the Bible

Then Abimelech called Abraham and asked him, "What have you done to us? How have I sinned against you, that you have brought such great sin against me and my kingdom? You've done things to me that ought not to have been done."

So I thought to myself I ought to tell you that you must make a public purchase of this before the town residents and the elders of my people. So if you intend to act as the related redeemer, then do so. But if not, let me know, because except for you and I after you there is no one to fulfill the duties of a related redeemer." The man responded, "I will act as related redeemer."

So one of the priests whom they had carried away from Samaria went to live in Bethel to teach them how they ought to fear the LORD.