'Forgotten' in the Bible

“When you reap your harvest in your field and have forgotten a sheaf [of grain] in the field, you shall not go back to get it; it shall be for the stranger, for the orphan, and for the widow, so that the Lord your God may bless you in all the work of your hands.

You shall say before the Lord your God, ‘I have removed the sacred portion (the tithe) from my house and also have given it to the Levite, to the stranger, to the orphan, and to the widow, in accordance with all that You have commanded me. I have not transgressed or forgotten any of Your commandments.

Then it shall come about, when many evils and troubles have come on them, that this [sacred] song will confront them as a witness; for it will not be forgotten from the mouth of their descendants. For I know their inclination which is developing even now, before I bring them into the land which I have sworn to give them.”