Albert Barnes Commentary Psalms 78:29

"So they did eat, and were well filled; And he gave them their own desire." — Psalms 78:29 (ASV)

So they did eat, and were well filled - The word rendered “well” here is intensive. It means that they were abundantly satisfied; that there was no lack; that they had the most ample supply.

For he gave them their own desire - He gave them exactly what they asked. He gave them flesh to eat as they had demanded; and he gave it to them in such quantities that no one could say that he had not enough.