A Hebrew rabbi once taught his students the Psalms of David. He did so by saying “Turn in your psalter to Psalm one hundred and sixty six.” One of his students, eager to point out the rabbi’s error said, “Rabbi, there is no Psalm 166. The last Psalm is 150”. The rabbi wittingly said “I said not Psalm 166. I said Psalm 100 AND 66.”

Notice the similarity in the beginnings of these two Psalms...

“Make a joyful noise unto the LORD, all ye lands.” (Psalm 100:1)

“Make a joyful noise unto God, all ye lands:” (Psalm 66:1)