Genesis 21:30

And he said, For these seven ewe lambs shalt thou take of my hand that they may be a witness unto me that I have dug this well.

Genesis 31:52

let this heap be witness and this pillar be witness that I will not pass over this heap against thee and that thou shalt not pass over this heap and this pillar against me, for harm.

Genesis 31:44-48

Now therefore come thou, let us make a covenant, I and thou, and let it be for a witness between me and thee.

but that it may be a witness between us and you and our generations after us, to do the service of the LORD before him with our burnt offerings and with our sacrifices and with our peace offerings that your children may not say to our children in time to come, Ye have no part in the LORD.

Joshua 24:27

And Joshua said unto all the people, Behold, this stone shall be a witness unto us, for it has heard all the words of the LORD which he spoke unto us: it shall be, therefore, a witness unto you lest ye deny your God.