Some have observed that psalm 81 appears to refer to the observation of the
Feast of Trumpets in Egypt. This has confused them and they ask how this
festival could have been observed in Egypt when Israel left in the spring.
This is a valid question and psalm 81 needs some explaining.
PSALM 81
Blow up the trumpet in the new moon, in the time appointed, on our solemn
feast day. For this was a statute for Israel, and a law of the God of
Jacob. This He ordained in Joseph for a testimony, when he went out
through the land of Egypt (margin; when He went out against the land of
Egypt) Psalm 81:3-5.
First, notice that David is writing to his readers, NOT to the people in
Egypt, who lived many hundreds of years before he was born. He was
telling his READERS who were, in David's day, NO LONGER living in
Egypt to; Blow the Trumpet in the new moon. David then goes
on to declare that his readers should do this BECAUSE it was ordained in
Joseph at the time that the tribes of Joseph left Egypt (margin it was
ordained when God went against Egypt).
The explanation is that; We are to observe this festival because
God ordained (commanded) that we do so. He gave this command to our
forefathers at the time that they came out of Egypt.
